I think people overestimate the awkwardness, here. Microsoft just wants to sell game copies - if they make money selling a really cool experience to Playstation owners, it's a win-win. We would know if Microsoft was envious of the PSVR sales numbers, by now.

They already support the game in Windows Mixed Reality, and the VR is already playable on non-Microsoft platforms through Proton. This seems like a really cool gesture from a dedicated software team that didn't want PS5 owners to feel disappointed buying Microsoft games.