I think it makes sense to deliver their games only through their ecosystem. Make your ecosystem support every one of their games is a clear priority over porting a game outside of their ecosystem. For bringing gaming to more people, the plan is to expand the ecosystem. They seems very open minded to put it even on Playstation and Nintendo Switch.
But it also makes sense for Sony to not want the MS ecosystem on Playstation.
So, if we do not have Bethesda games on PS5, i woldnt blame any of the companies.