Sony will very likely eye an acquisition (possibly even the one extensively rumoured over the years that isn’t Square Enix)

Sony won’t be allowed to since they’re the market leader by a long way.

Honestly, the biggest thing holding back Sony ports to Xbox is probably Microsoft’s insistence on platform support for the Series S.

No, it’s that sony don’t want to release their games on xbox. Don’t be silly. Playstation basically is Sony these days. Everything else they own has either died or faded into irrelevance apart from cameras and tvs. Playstation is their biggest asset, and they would never consider releasing their games on their competitors consoles.