Srila Gour Govinda Swami was fond of referring to the Caitanya Caratamrita wherein its stated that Sri Caitanya Mahāprabhu has infused the names with Vraja prema ..and garlanded the whole world.
Srila Jiva Goswami in the Tattva Sandarbha says Krishna accepts names  given to Him by His devotees , He accepts  names because of the Bhakti  of His devotees. Mahāprabhu chanted many names of God , which He had accepted, and also when He appeared  He enthuses them all with prema Rasa of Vrndavana.
So although the names of God when chanted purely have always brought relationships  with God  , however when  Mahāprabhu came He revealed the most perfect of all spiritual relationships, those of the residents of Vrndavana which are situated in pure spontaneous love free from awe and reverence. Mahaprabhu brought newer and newer meaning to what it means to love God and revealed everything via chanting the pure names of God , chanting is the means and the end of spiritual perfection. The Pranaya of Manjari bhava has been revealed, and the abode of supreme love , that is within the heart of Srimati Radharani , has been somewhat revealed through the process of chanting the names that Mahāprabhu has accepted and through the nine fold processes of  devotion discussed by Srila Rupa Goswami , beginning with and ending in chanting and meditations of Radha Krishna lila .and the other lilas in Vraja.
Our acaryas give indication of the newly enthused and changed order of the Maha mantra. With Hare Krishna coming first , instead of Hare Rama first . The competition of the love between the Radha Krishna of Vrndavana is revealed , but in their most perfect parakiya Rasa .
Sri Caitanya Mahāprabhu chanted Hare Krishna and also many other names of God .  Through the teachings of Mahaprabhu to Rupa Ragganatha and the Goswami’s of Vrndavana this Mantra meditation has been revealed…and Srila Bhaktisiddhanta Sarasvati Goswami made efforts to formalise and regulate , its chanting ,  Srila Ragganatha das set an example and chanted in scheduled ways , as did Haridas Thakur.
Srila Sridhar says this …in regards to some historical information.


Commenting on this enigma, Srila Sridhara Deva Gosvami Maharaja has stated as follows:

“The real importance of the Name is not to be found merely in the arrangement of its syllables, but in the deep meaning within that divine sound. Some scholars argue that in the Kali-santarana Upanisad, Lord Brahma says that the Hare Krsna maha-mantra is properly pronounced only when the Name of Rama precedes the Name of Krsna:

hare rama hare rama rama rama hare hare
hare krsna hare krsna krsna krsna hare hare

“In the Kali-santarana Upanisad, the Hare Krsna maha-mantra is given in that way. But to say that the Name of Rama must precede the Name of Krsna in the mantra is a superficial understanding.

“It is said that because it comes from the Upanisads, the Hare Krsna mantra is a Vedic mantra, and therefore, because the ordinary people may not have any entrance into Vedic mantras, Sri Caitanya Mahaprabhu readjusted this mantra by reversing the order of the words. In that way, it is said, the concern that it is a Vedic mantra is thereby canceled, and so Sri Caitanya Mahaprabhu gave it to all without breaching the injunctions of the Vedas. Some devotees in Uttar Pradesh who have great affection for Sri Caitanyadeva like to give this opinion. But our faith is that the mentioning of ‘Hare Rama’ first is only superficial. It concerns the idea that since the Rama avatara appeared first and the Krsna avatara afterwards, the Name of Rama, ‘Hare Rama,’ should come first in the maha-mantra.’

“A deeper reading will consider that when two similar things are connected together, the priority will be ordered not on the basis of historical precedent, but in consideration of the most highly developed conception. The Holy Name of Krsna is higher than the Holy Name of Rama. This is mentioned in the Puranas: three Names of Rama equal one Name of Krsna.’

“The Name of Krsna is superior to the Name of Rama. Where the two are connected together, the first position should be given to the one that is superior. Therefore, the Name of Krsna must come first in the maha-mantra. This is one point.’

“Another point is that within the eternal plane, everything is moving in a cyclic order. In an eternal cycle, which is first and which is next cannotbe ascertained, and so, in the eternal plane of lila, it cannot be determined whether Krsna is before Rama or Rama is before Krsna. So from that consideration also, since the Names of Krsna and Rama are eternal andunrelated to any historical event, we may begin the mantra from any place.’

“But above these considerations, our sampradaya has given another, higher consideration. A eeper understanding will reveal that the Hare Krsna mantrais not at all concerned with rama-lila.’

“In the Name of Rama within the Hare Krsna mantra, the Gaudiya Vaisnavas will find Radha-ramana Rama. That means, ‘Krsna, who gives pleasure (raman) to Srimati Radharani.’ In our conception, the Hare Krsna mantra is wholesale Krsna consciousness, not Rama consciousness.’

“Sri Caitanya’s highest conception of things is always svayam bhagavan, krsna-lila, radha-govinda-lila. That is the real purpose of Sri Caitanya Mahaprabhu’s advent and teachings. In that consideration, the Hare Krsna mantra does not mention the rama-lila of Ayodhya at all. There is no connection with that in the highest conception of the Hare Krsna mantra.’

“And the inner conception of the mantra is responsible for our spiritual attainment. When one pronounces the Name of Rama, if he means Dasarathi Rama, his attraction will take him there, to Ayodhya; if he means Parasurama, he will be attracted to another place. And if Rama means Radha-ramana Rama, he will go to Goloka. The inner conception of the devotee will guide him to his destination.” (Loving Search For The Lost Servant) of their devotion.

Mahāprabhu chanted many names of God , which He accepts and enthuses with Rasa .
So although names of God when chanted purely have always brought relationship with God , however Mahāprabhu has given new meaning , the Pranaya of Manjari bhava and the abode of love Srimati Radharani is somewhat revealed , through the names that Mahāprabhu has accepted.
Our acaryas give indication of the newly enthused and changed order of the Maha mantra. With Hare Krishna first , and the Radha Krishna of Vrndavana revealed , in their most perfect Rasa .
So Mahāprabhu chanted Hare Krishna and many other names , but through Rupa Ragganatha and the Goswami’s taught this Mantra ….and Srila Bhaktisiddhanta Sarasvati Goswami made efforts to formalise and regulate , also Srila Ragganatha das chanted in scheduled ways , as did Haridas Thakur.
Srila Sridhar says this …in regards to some historical information.

Commenting on this enigma, Srila Sridhara Deva Gosvami Maharaja has stated as follows:

“The real importance of the Name is not to be found merely in the arrangement of its syllables, but in the deep meaning within that divine sound. Some scholars argue that in the Kali-santarana Upanisad, Lord Brahma says that the Hare Krsna maha-mantra is properly pronounced only when the Name of Rama precedes the Name of Krsna:

hare rama hare rama rama rama hare hare
hare krsna hare krsna krsna krsna hare hare

“In the Kali-santarana Upanisad, the Hare Krsna maha-mantra is given in that way. But to say that the Name of Rama must precede the Name of Krsna in the mantra is a superficial understanding.

“It is said that because it comes from the Upanisads, the Hare Krsna mantra is a Vedic mantra, and therefore, because the ordinary people may not have any entrance into Vedic mantras, Sri Caitanya Mahaprabhu readjusted this mantra by reversing the order of the words. In that way, it is said, the concern that it is a Vedic mantra is thereby canceled, and so Sri Caitanya Mahaprabhu gave it to all without breaching the injunctions of the Vedas. Some devotees in Uttar Pradesh who have great affection for Sri Caitanyadeva like to give this opinion. But our faith is that the mentioning of ‘Hare Rama’ first is only superficial. It concerns the idea that since the Rama avatara appeared first and the Krsna avatara afterwards, the Name of Rama, ‘Hare Rama,’ should come first in the maha-mantra.’

“A deeper reading will consider that when two similar things are connected together, the priority will be ordered not on the basis of historical precedent, but in consideration of the most highly developed conception. The Holy Name of Krsna is higher than the Holy Name of Rama. This is mentioned in the Puranas: three Names of Rama equal one Name of Krsna.’

“The Name of Krsna is superior to the Name of Rama. Where the two are connected together, the first position should be given to the one that is superior. Therefore, the Name of Krsna must come first in the maha-mantra. This is one point.’

“Another point is that within the eternal plane, everything is moving in a cyclic order. In an eternal cycle, which is first and which is next cannotbe ascertained, and so, in the eternal plane of lila, it cannot be determined whether Krsna is before Rama or Rama is before Krsna. So from that consideration also, since the Names of Krsna and Rama are eternal andunrelated to any historical event, we may begin the mantra from any place.’

“But above these considerations, our sampradaya has given another, higher consideration. A eeper understanding will reveal that the Hare Krsna mantrais not at all concerned with rama-lila.’

“In the Name of Rama within the Hare Krsna mantra, the Gaudiya Vaisnavas will find Radha-ramana Rama. That means, ‘Krsna, who gives pleasure (raman) to Srimati Radharani.’

In our conception, the Hare Krsna mantra is wholesale Krsna consciousness, not Rama consciousness.’

“Sri Caitanya’s highest conception of things is always svayam bhagavan, krsna-lila, radha-govinda-lila. That is the real purpose of Sri Caitanya Mahaprabhu’s advent and teachings. In that consideration, the Hare Krsna mantra does not mention the rama-lila of Ayodhya at all. There is no connection with that in the highest conception of the Hare Krsna mantra.’

“And the inner conception of the mantra is responsible for our spiritual attainment. When one pronounces the Name of Rama, if he means Dasarathi Rama, his attraction will take him there, to Ayodhya; if he means Parasurama, he will be attracted to another place. And if Rama means Radha-ramana Rama, he will go to Goloka. The inner conception of the devotee will guide him to his destination.” (Loving Search For The Lost Servant)