Yoboman
has made several posts explaining about "tying". Coercing the service onto PS is not an option - so, leveraging IP to make a deal is not a realistic plan. The thing about the titles you mentioned is that MS has been working hard to make them playable on multiple devices. If people want to play them, they can - on Xbox, PC, phones, etc. GamePass on PS is not the only way to play these games for people not in the XBox ecosystem.
I suppose this is a wait and see situation, but the fact that Sony has indicated no interest in having GamePass on PS and are creating their own sub services seems, to me, to indicate GamePass will not be appearing on PS. As well, there is little financial incentive for Sony to do so.