Ah, gotcha, I thought you meant the main dev team alone when I replied.Yeah, that's one of the things I said that can be done beforehand but for them to actually develop the game already and the main KH team to join'em after that isn't gonna happen but preparing everything and do little stuff to make future work run much faster and easier, that's something I can see that they'll do. But I'm pretty sure that for KH3, every team that has already worked on KH will join development to fasten development, especially the Osaka team.
I wouldn't be surprised if a small portion of this was finished already with some of the down time FFvXIII has had. It's been in development fpr as long as the PS3 has been on store shelves, and while the game is practically finished it's still only just recently entered full production.