Worlds Disney Won't Let Nomura Use For KH (& the Worlds Disney Wants but Nomura Doesn't):
Toy Story: Nomura refused to make KH3 until Disney let him use Pixar... and thus Toy Story. Toy Story seems to have set up much of the premise of Phase 2 of KH & the emotional resolution of Phase 1 (saying goodbye to childhood, to Kairi).
Frozen: there are Theory Vids on YT that go into the idea in depth but, ultimately, it amounts to Disney changing its mind about letting Elsa have a Heartless between bringing Frozen up to Nomura BEFORE the film's release, the development of KH3, the successful reception of Frozen & susequent planning for a sequel, then the release of KH3. Elsa going Full Riku, Sora seeing her conflict firsthand (as opposed to in KH1 & the Anna POV KH3 ended up with) would have better enabled Sora's Context for RIKU'S villain arc (& why he was able to redeem himself).
High School Musical: the HetNorm analogies of musical theatre & Chad getting Mad at his best friend for [leaving him behind/having a girlfriend], followed by Everything About Ryan & Chad in HSM2... THOSE are the themese Nomura would be interested in & he'd even figure out how to make Basketball Heartless INTERESTING in order to use them. RIP Chad/Ryan.
Lilo & Stitch's World AND Moana's World: we will get one or the other, never both because Disney would see TWO indigenous islander girls & consider their stories interchangable. The only loophole I could think of that would enable both worlds to exist in the same game would be if Lilo's World was the "Future" of Moana's. As is, it seems Inevitable that Nomura will ask to use Moana: whether it's to compare Moana with Riku (island kids who want to explore, who get bad advice on heroism but ultimately choose 'love', who have Explorer Ancestors) or in parallel with Kairi (who is now starting her OWN journey, independently of her friends, and will ultimately lead her back to her forgotten roots)... Nomura will get his "playble Island World". If Stitch conveniently crash lands halfway through Moana's journey? EVEN FUNNIER.
The Goofy Movie: imagine getting Goofy Backstory all of a sudden, complete with the Awkward Realization that Goofy has had a Grown Up Son back home that Sora has been reminding him of. o_o;
Cinderella 3: this film is basically Chain of Memories but EXPLICITLY ROMANTIC. it would, hilariously, cast Naminé as Anastasia AND as 'Fairy Godmother'. The return to Cinderella's World JUST to emphasise Sora as CinderRiku's 'Dream'... using the Oblivion Keyblade & Sora's Necklace as a narrative glass slipper might even be overkill by that point.
Maleficent: Nomura probably wouldn't be interested in using a story about parental love, at this point in the series, except to point out Maleficent was Riku's Evil Fairy Godmother in KH1 & will be having her Comeback now that CinderRiku is rescuing his Prince Sorara with True Love... AGAIN (DDD's plotline is essentially the same as Sleeping Beauty's). There's no need to include Maleficent's World when its plot is playing out with the KH-original cast - it would be background repurposing to clarify narrative intent. though, given how slow audiences are about picking up on non-het romantic subtext... Nomura MAY need Maleficent's home turf after all.
Star Wars: it would be kind of redundant to have Jedi in KH unless they were redressed as ancient Keyblade Wielders. Star Wars would only hammer in the "Xehanort was actually Anakin Skywalker, now you need to find his Palpatine" thing for KAIRI & the Wayfinder Trio (who any present-continuation plotlines of Ancient Masters would naturally fall to).
being in a dead fandom is like being in a humid cave alone in the summer but then you find something sparkle in a corner with a bunch of dust on top and its a 2015 masterpiece of a fanfic that you will think about it till the day you die
It is so funny when Troy was like “Oh no! Ryan is flirting with Gabi!” Like Troy I’m sorry your gaydar is so bad but he is NOT flirting with your girlfriend.