Kingdom Hearts 4 will feature Disney world, but we should expect to see fewer of them than anticipated, judging from a new statement from Director Tetsuya Nomura.
In a new interview posted on Game Informer, Tetsuya Nomura has been asked how much will the Disney characters and worlds be important in the next entry in the series. The game's director confirmed that there will be Disney worlds, but the fourth entry in the series will generally feel slightly different from the previous games. Apparently, the increased specs and better visuals of Kingdom Hearts 4 limit the number of worlds that can be created for it.
As far as the graphic qualities ... since with each new title, the specs have been really increasing and there's so much more we can do in terms of graphics, it kind of limits the number of worlds that we can create in a sense. At this time we're considering how to approach that, but there will be Disney worlds in Kingdom Hearts 4.
In the same interview, Tetsuya Nomura was also asked about the lack of Final Fantasy characters in Kingdom Hearts 3. According to the series' creator, the Final Fantasy characters were originally added to the first entry in the series due to the limited amount of original characters in it, which stopped being a problem in the following entries in the series. Still, the development team is aware of players wanting to see more Final Fantasy characters in the next entry in the series, and they are trying to find a good balance for it.
With Kingdom Hearts III, since we did have so many original Kingdom Hearts characters, it was hard to find room for including more Final Fantasy characters. We're trying to find a good balance for that. I know that some fans were concerned about that and weren't too happy and wanted to see more Final Fantasy characters. That's something we definitely are thinking about. But just with the sheer number of original characters that we have now, it's hard to say what the exact balance is going to be and how it will play out in Kingdom Hearts 4.
Kingdom Hearts 4 is currently in development for yet-to-be-confirmed platforms. A release window has yet to be confirmed as well.