I really don't think Microsoft needs new studios. They need to get better performance out of the ones they have.
Umm, ok.
Not sure how Playground Games can do any better with Horizon. On top of that they are extending their abilities and scope by doing Fable as well. Not many studios out there like them.
Not sure how Turn 10 can do any better than Forza. They are upgrading their game engine and redoing Forza from the ground up. Pretty sure that is doing better.
The Coalition has done a great job with Gears and are considered to be the best developer using Unreal Engine, even by Epic themselves.
Ninja Theory are a known quality developer, and are working on a AAA sequel to their Smash hit Hellblade 2.
Obsidian are one of the best bang for the buck studios out there and could be said to be Xboxs best studio.
InXile are a quality RPG studio, and just released Wasteland to very good reception. They are now working on a new IP with a much bigger budget and scope than ever before. Not sure how they need to do better.
Double Fine recently released Psychonauts 2 and it recieved a great reception and a 87 meta. Not sure they need to do better.
Rare last game SOT is a massive hit with around 30 million people playing it. Again, pretty sure they don't need to do better.
Undead labs are upgrading from an Indie studio to a AAA studio. That's pretty much the idea of doing better.
Bethesda are releasing their biggest new IP in generations in Starfield. On top of that they have a new Elder Scrolls and Fallout in their future. They can't do much more than that. Todd Howard...
Arkane coming off the acclaimed Deathloop and backing that up with Redfall. They are an elite studio.
Id have come off the amazing Doom Eternal. Like, they don't need to answer to anyone about doing better.
Tango just released Ghostwire. Not a bad game.
Machine Games are working on a new Indiana Jones game after coming off the great Wolfenstien ones. Again, no need to up their game here.
Mojang continue to run one of the biggest and most loved gaming franchises ever in Minecraft.
Roundhouse are working on a new Xbox IP as well as helping with Redfall. Everyone bitching about Xbox needing more new IPs should be thankful for it.
World's End are working on the Age Of Empires IP and released the last one to good reviews. They are doing their thing on a known IP. Not sure they need to be better.
That brings us to the last two.
343. They released the excellent Halo Infinate campaign which was a return to form. Outside of that they have been less than stellar and the multiplayer side of the game has been a massive cluster fuck. Microsoft has taken action and moved on those who didn't pull their weight.
The Initiative. Setting up a new studio from the ground up is a massive task. You don't have any offices, no dev kits, no staff, no set engine and assets to work from. Then throw in covid, and the studio has suffered. However, action has been taken and now Crystal Dynamics are taking the workload on at the direction of The Initiative.
So as you can see it's a beat up to talk about how Microsoft need to get their studios sorted out. I understand it's mostly concern trolling, but nether the less.
All in all, it's moving in the right direction for MS to give people no reasons not to play their games.