If it goes back to it, it needs to go back to the X-2 version. Honestly the ATB up until that point was fairly garbage, and X's CTB was preferable in almost all circumstances.

I'd love to see a return to some kind of turn based, certainly. Although I can live with action oriented gameplay if it has good story, characters and deep RPG systems behind it to back it up. XV's major gameplay issue was the lack of meaningful meta-game outside the hack and slash combat. It was fun, but shallow.