Here's a recap of what's been confirmed for Kingdom Hearts III so far in terms of worlds: Tangled, Toy Story, Big Hero 6, Monsters Inc., Hercules, Twilight Town, and Yen Sid's Tower. We also know that "no Final Fantasy worlds" are in. For a nebulous "2018" release that's not too bad in terms of info, but a new leak might have given us more insight if it's correct.
Spoilers, obviously.
via destructoid https://www.destructoid.com/rumor-more-potential-kingdom-hearts-iii-worlds-leak-494583.phtml