I think I said this before, but I would love for KH4 to be a time gap, so HJO can voice an older character and we can have worlds like Return to Neverland and travel around with Wendy's daughter, Simba's Pride where we can help Simba be a Father, A Goofy Movie with Goofy's son Max and see Sora's surprise that Goofy is now a Father and have a Powerline Summon. And it would also be cool to experience how much has changed since the very beginning of KH1 and some of us who have grown up with the first game are parents ourselves now, or about to be.
There was even a review of KH3 by somebody's young daughter experience of the game with the opening Hercules world.
Also Treasure Planet instead of Pirates, omg, please. No more Jack Sparrow and Elizabeth Swan.
Though, I don't think we'll see this game till at least the middle of the PS5's lifetime, or maybe even at the beginning of the PS6.