Blizzard has already been doing that for a while. Also failing with new franchises, not investing in their core games, half assing releases. I hope they actually turn things around for games like Starcraft, Diablo, HotS etc
Blizzard would never have done that if Activision hadn't been allowed to buy them. The new conglomerate will be worse than we anticipate in the same way Activion-Blizzard was.
Blizzard had pretty much only made amazing games before Activision bought them. Activision also made a lot of good games back then. People couldn't see how the merger would fick it up back then, yet it still did.
I expect Bethesda to get infected with the worst that Activion-Blizzard has to offer more so than the opposite.
Most of those are already shit (Fallout, Diablo, Overwatch, call of duty) or shelved 25+ years ago (Commander Keen, Hexen, Phantasmagoria...). Microsoft's own games are rather good compared to Activision Blizzar or even Bethesda.