There's quite a few Square Enix games I wouldn't mind: Deus Ex, Hitman, NieR:Automata, Kingdom Hearts and FFXV.
FFXV is getting an extended/alternate ending DLC, so they might look to release it the same time with all the content.
I think it's too late for FFVX. It's also quite improbable that Switch can handle it. I would much rather have Kingdom Hearts 3.
I would think from a visuals point of view SE wouldn't sign off on a Switch port of KH3, realistically we sort of know what to expect from Panic Button and that is a very good port where the game and mechanics survive perfectly onto Nintendos little beast, but where the visuals take a (sometimes) huge hit in comparison to the HDTwins of MS and Sony, figure that Disney and Square would have considered this and opt not to bring something like KH to the system because they've always been about maintaining the image of their IPs as best as possible
I'm well aware that KH has made appearances on both the PSP and DS/3DS but those were all games created for those platforms with a visual style created for them from the ground up, I think the porting of something like KH3 to the Switch would create a very muddy version of that title rather than something made from the ground up for it.