Today, during a panel at D23, it was announced that Big Hero 6 will be a world explored in the upcoming Kingdom Hearts III. The property now joins Tangled on the confirmed list of places you'll be able to explore in the Square Enix cross over, and honestly, I think it makes a lot of sense. Superheroes, action, Baymax, it all fits.
The world in-game will take place after the movie, so the Big Hero 6 team will already be assembled and ready to fight alongside. Besides that, we weren't told much, but hopefully we will hear something about more worlds soon.
Take a look at the announcement here.