I don't see how they could drop the FF characters, especially when some are still fairly vital to the story. Leon and Cloud mainly. It's not like Sora can just wake up and say, "Man! All my friends were imaginary! Good thing I still have Disney characters!" haha. They can't go backwards in plot design. It is what it is. They should just expand now, with FF characters, Disney characters, and original characters.

Now, IF they went into some FF worlds, that might be a little much.... going from Atlantica to Spira or whatever. haha