Probably not fully, unless they actually do work on the games. The cutscenes on some of the games play with a proprietary protocol that even Proton-GE can’t run. So, while the game works, the cutscenes don’t.
It’s feasible that they will fix it, but I consider it highly unlikely.
Kingdom Hearts is coming to Steam - June 13 (files.catbox.moe)
Source: x.com/KINGDOMHEARTS/status/1792722028354818287