For the Sora vs Aqua placeholder comments, back when I first saw that fight that was exactly what I thought it was. The game was still in production and a lot of the data in the fight just felt demo ish. The health, keyblade, and other factors just kind of felt like it was constructed for the battle and it isn't very difficult to do asset swaps for demos. Doing something along those lines does more than just hide Riku, it can hide when the fight happens in game, how far along in character progression you are. Honestly with how much the community analyzes every tiny facet of these trailers I'm surprised so many take them at face value. The fight didn't even have much of a cutscene before it, just a quick shot of Aqua as a darkling (personal theory, I doubt she's norted) then the battle.
These don't really count as false advertising either since most demos are built out of in process assets and that footage hasn't been used in anything since. All it did was show that she was a battle, which is what it was meant to do while also showing her new look. We already had various cutscenes shown where she is talking to Riku and Mickey and we knew that was their mission.
This kind of feels all over the place, but this kind of thing is very common in games. Just because something is shown in a trailer doesn't mean it is in the game, or at least in the game as is. There are some demos I've seen in games that have little to nothing to do with the final product once all was said and done (Borderlands is a good example of this). Just look at the trailer for Cyberpunk, a game where no one knows when it's coming out and when they released their gameplay footage there wasn't a single moment when they didn't stress that it was in production and something will not be the same in game.
Sorry for the rant but this thread of thought has been really bugging me every time it pops up.
