Final Fantasy games aren't usually made into movies. In fact there has been only 2 of them. Final Fantasy: The Spirits Within is not a sequel, prequel, or spin-off of any Final Fantasy game. While Final Fantasy VII: Advent Children was a sequel to the playstation title. No other movies exist that relate to the other Final Fantasy game titles.
I'm not quite sure what you're saying, I think I got the gyst of it though. Do you mean for Square to make Kingdom Hearts 3 into a movie, then make a game based off of it (or vice-versa)?
What would be the point of that? I would only imagine Square would be doing that as a way to earn money off of Kingdom Hearts. A game or a movie, not both. Besides I doubt Square would do production on both, and I'm sure Nomura would only settle for one or the other. So the chances of that happening are slim.