Well of course. Xbox is an open ecosystem, because of that Zenimax's games will be on PC and xCloud as well as Xbox, so there are more options for Sony fans to still play Zenimax games day one if MS decides to not allow them on PS5. Sony on the other hand would have locked those games to PS5, possibly not even allowing day one PC releases for them, which would have had both Xbox and PC gamers furious (PC is Bethesda's largest fanbase, not Xbox, with a massive modding community for their games).
There is also the fact that Bethesda (and id and Arkane) have past history with Xbox, Bethesda Softworks has always been associated with Xbox as a result of that, so of course Xbox fans would have been furious if Sony hatted a formerly Xbox associated publisher away from Xbox. Sony acquiring Bethesda and then making their games PS5 exclusive would have been roughly equivalent to MS acquiring Insomniac, Quantic Dream, and Housemarque, and then locking them all off from releasing on PS5, Sony fans would go nuclear if that had happened.
What? Bethesda has published all their games to Sony platforms for about 14 years now. How in the world is that equivalent to MS purchasing Insomniac (a studio which almost never released games on Xbox)?
Even if Sony had simply locked Bethesda games out of Xbox, while still allowing them on PC, Xbox fans would have blown a gasket. There would have been several posts in all caps. I've yet to see any all caps posts from Playstation users.