4a is not owned by deep silver though, they're a private company I believe
Deep Silver is just a publisher for Metro franchise. They don't own 4A Games.
4A is an indie studio. Deep Silver is just the publisher.
I know, but Deep Silver own the IP and they have a long-term partnership with 4A. Why would 4A suddenly choose another publisher?
There is a common point between Obsidian, inXile, Playground Games, Undead Labs, Ninja Theory and Compulsive Games: they wanted the long-term security that Microsoft can gives them. They want to stop to go from publisher to publisher, without knowing what they will do if they don't find anything.
But 4A is in a different situation. They worked with Deep Silver since 2013. Their games were critical and commercial success, they don't seem to have any problem with their publisher and I doubt THQ wants to stop working with them.
The question is not "would those studios be good for Microsoft", neither "would we like to see these studios as part of the Microsoft family", but "what can Microsoft give to them?"
I don't see any reason for 4A Games to join Microsoft. And the same is true for Relic and Creative Assembly. Sega is maybe the best publisher that a studio can have. They let a total freedom to theirs studios and don't want to an absurd growth. All the monetization of the game is chosen by the studio itself, not by Sega. Why would they agree to risk all of this? And why would Sega sell one of its more important studio?
For me, it doesn't make more sense to discuss the purchase of 4A Games or Creative Assembly than about CD Projekt, EA or Nintendo. We have many reasons to think it won't happen and none (or very few) reason to think it will.
Yes, we are on a forum. We won't change the world. But I think it's more interesting to make realistic guess. We're not here to discuss what our dream purchase would be, but what studio Microsoft could buy.