Honestly, I don't want them to put in Disney bosses just because 'hey, you get to fight Disney characters!'. This is supposed to be the end of the Xehanort saga, so if 99% of boss battles aren't Disney characters, I'll honestly be fine with that since there are still plenty of loose ends they need to tie up in the original story.
I mean, I kind of agree with you but there's tons of ways to put disney bosses, Nomura already said there's middle bosses so... lol