Also, just want to add: I don't understand this trend in thinking bigger is necessarily better. Perhaps I'm just old, but most recent games I've played that have boasted huge worlds have been more tedious than interesting. I get annoyed if it takes a long time to traverse an area that doesn't really benefit from being so big. My experience with FFXV comes to mind: gorgeous world, but a nightmare to navigate. One of my bigger fears for the FFVII remake is that cities like Midgar will be so massive that they'll be a chore to explore.
I haven't watched any of the leaked gameplay videos for KH3, but I'm not going to be bummed if the worlds aren't enormous. I want them to be only as big as they need to be. In other words, big enough to feel a sense of wonder, but not so big (and void of meaningful activities) that it feels taxing to traverse from one place to another.
What if the world is just two rooms?
I don't think anyone here wanted TT to be bigger than it was in KH2, but it could have at least been better. Now it's neither.