They won't be closed - they will be turned into single franchise assembly lines making new games as service products every 2-3 years just like all current Microsoft studios.
Alright so, I see alot of people making jokes about how " HUURR DUURRR each MS FP studio only makes one game." So I'm gonna lay it out here and be as clear as possible for the people who literally refuse to understand.
343i- Literally created to continue with creating content within the Halo IP
The Coalition- Literally bought to continue with creating content within the Gears IP
Turn 10- Literally created to make and continue making Forza
Mojang- Literally bought to continue creating content within the Minecraft IP
Rare- Allowed to do whatever they want as of recent
Playground- Allowed to do whatever they want
Ninja Theory - Allowed to do whatever they want
Compulsion - Allowed to do whatever they want
The Initiative - Created to create new IP for XBOX
Undead Labs - Bought with the intent to continue creating State of Decay (they expressed interest in continuing with the IP)
Obsidian - Allowed to do whatever they want
inXile - Allowed to do whatever they want
Mojang, The Coalition, Turn 10, 343 and Undead Labs and I suppose Playground team 1
ALL want to continue creating within their respective franchises. They all have literally expressed this. So having said that, no I don't believe Obsidian and inXile will be forced to continue on making the same thing over and over.
But while we are on the topic, lets look at Sony and their studios shall we?
Four of their studios all literally move from one IP to the next and beat the shit out of it until I assume they run out of ideas. But they aren't forced, are they?