Well think about it, most games that came after KH1 (except for KH2 but there are exceptions to some worlds) were on handheld consoles when it came to how worlds would be viewed. Imagine the big worlds in KH1 "fitting" into the gameboy advance, DS, PSP, and 3DS. I mean I never liked the fact that the worlds were smaller but to make up for that I think the worlds had more to offer in terms of story line, game play, and even mini-games.
Going back to the main topic. I do think that in terms of commercializing (since Disney is in part a business) it doesn't surprise me that these rides in the game would be from the actual parks themselves. I think of it as a way to show kids "these rides in the game are actually real!" which is cool!