It's still not an existing IP. Sony fans have not been deprived of any titles they've been able to play for years. Outside of Bethesda, Microsoft also owns Mojang and Minecraft. That a hugely successful title that is still available on multiple platforms. Microsoft could have taken that away. They could have taken Fallout, Skyrim etc away but they haven't.

If Sony had the money to do the same thing Microsoft is doing, would they do things any different than Microsoft? Sony's exclusive developers/games remain exclusive to their consoles. The outrage seems to be that you and everyone else hates that Microsoft has more money. But unless they take all these pre-existing titles away, what is there to really complain about?