Back to the original point....

Unless Microsoft has relented on its demands, the game has no chance of being moved onto XBox at this time. There were three major issues in the past (two of them connected) that had stopped the game from going to that platform. Microsoft didn't want cross platform play, and insisted on XBox exclusive servers. The first of these issues I can see Microsoft not making a thing anymore since they've been attacking Sony these days for not allowing cross platform play, but I do not know if they still want exclusive servers, since they did say that wanted to give their player base the option to not play with people on PC or PlayStation.

The second pain point was Square demanded that Microsoft not gate access to the game behind XBox Live. PlayStation users are not required to have PlayStation+ in order to access the game, and PC players don't have a gatekeeper cost keeping them from accessing the game beyond just the game's subscription. Microsoft didn't want to have an online game bypassing their fee to let people game online, and this was another point Square was very adamant about.

Additionally, since Sony has been resistant to cross platform play, they would have to get them to sign on to allowing XBox players to play with Sony.