6. Tomorrowland
Tomorrowland is a region of the Magic Kingdom in DisneyWorld and DisneyLand but is also set to become a movie of the same name. What better way to prepare ourselves then, than by being able to explore the section of the park in Kingdom Hearts III? Its future, mechanical setting could provide an interesting backdrop to the world, while tying together a lot of Disney franchises. What's more a moving escalator that ties the whole region together could be a great place for a battle with the Heartless or maybe even a boss battle. Tomorrowland could be a standard world with a story, or it could be a great HUB world for Sora, creating a bridge between all the other worlds. Also, in Tomorrowland is home to a little ride known as StarTours, and while I think that a Star Wars world is out of the question, it could be a great place for a C3PO and R2D2 cameo. You never know, it could happen. I wouldn't hold out hope for Darth Vader though.