That's not at all how Disney works, though. Lasseter et al. have been very careful about maintaining separate IP fiefdoms with distinct brand identities, to the point where Pixar characters, seven years after the Disney acquisition, are only now appearing in the same game as Disney characters, and only then in a carefully regulated fashion (all characters rendered in a consistent art style, no crossover allowed in the story mode levels, etc). Disney has only barely started even dabbling in crossing over Disney and Marvel IP (Phineas and Ferb: Mission Marvel), and that acquisition was a full three years ago.
On the other hand, Tron and PotC were created under the Disney umbrella, not Pixar or Marvel, so there's been little issue with crossing them over.
So if you expect KH3 to fulfill all your wildest Disney/Pixar/Marvel/Star Wars crossover fantasies, you're in all likelihood going to be very disappointed come... 2015 or whenever it ships.