Wish looks like a perfect world for KH4 thematically (assuming Asha turns out to be queer, for this to be on topic, but also, in itself it would be a fantastic addition to the franchise).
I could see Sora start this world with a wish to be reunited with his friends, and he would gradually learn that his true wish is to understand his own self, his own strengths, independently from his friends, so that he can return to them a better person. Having a queer sidekick could help him further process his feelings for Riku and Kairi, whatever they are, similar to how talking with Anna and watching the Frozen sisters together makes him reflect on his relationship with Riku in KH3.
Riku and Asha would be a fantastic duo, too.
If post-KH3 Kairi was playable, I could also see Asha and her have great conversations about meaningful relationships (Kairi about Sora) and their deepest Wishes. And defeating the bad guy together as girls who don't need boys. Asha could compare Kairi's thoughts about Sora to some thoughts she'd have about girls. It would just be a matter of a couple lines of dialogue, like Hercules talking about Meg in KH3.
The series does tackle love and friendship a lot so it wouldn't be a stretch to have queer love added to the mix of vague conversations about precious persons and whatnot, if they choose to include those Disney characters. My favorite examples are all the examples Sora witnesses in KH3 + Beast and Belle as witnessed by Roxas in Days (+ Beast in KH1). I'd rather have KH-speak about queer Disney relationships than out of the blue "I am this or that" lines of dialogue.
EDIT: The Baymax series is full of NPCs that would have been perfect to flesh out San Fransokyo in KH3! Too bad it wasn't out at the time
I don't see why SE would actively choose to remove LGBTI+ background characters if they are part of the Disney world chosen for their game. They can always edit them out of the Chinese release?