There's also the fact that Game Pass is still a non-starter on PC, even after all these years, so this could be Microsoft admitting that and going to a platform where cloud gaming on PC is actually doing rather well.
Same way they couldn't get Windows Store off the ground, so they were basically forced to turn to Steam. They would have avoided both scenarios if they could have afforded to. But I do think it's interesting if this is a step towards them moving into being a more full-on 3P publisher.
Did say a while ago, this deal would probably have been going a lot easier for them if they were actually a "real" 3P publisher. All games on all platforms Day 1 where it makes the most sense (i.e Starfield, Forza, Gears etc. on Xbox, PS, PC Day 1, Hifi Rush & Pentiment on Xbox, PS, PC, Nintendo, mobile Day 1, maybe the odd Age of Empires or Gears Tactics or Flight Sim being Windows/PC exclusive for a bit and then getting ported to Xbox & PS a little bit later) AND not presenting a conflicting business model (i.e they'd have to completely change how they handle "Day 1" on Game Pass for 1P titles, or offer extreme incentives for non-MS platform holders or do some crazy revenue sharing model that would more or less defeat the purpose of MS's Game Pass push as they've been leveraging it thus far).
If that were Microsoft's business model in practice by now, the deal would be going by much more smoothly. If they did all of that and probably even shifted Xbox into a PC-like business model on top of it(and allowed regular Windows to run on Xbox), this deal would have probably been approved before the end of last year.