The main reason is who is in charge at the time. Rather then the long standing positive partnership companies may have one new leader could step in and convince or force their decision on the company to sell to someone who obviously wouldn't be a good choice at all. For example wasn't the current Square Enix head pushing for NFTs and now they appear to be giving Gamepass a second go?
@Eternal_Wings I know you're active on following Square were the previous deals for FF7 Remake and FF16 before the new head stepped in do you know by any chance?