They were never under Xbox Game Studios to begin with.  Xbox Games Studios just shows up in the credits of some of their games because another studio helped with development and porting of their games like Turn 10 and Panic Button.

Playground Games was acquired by Xbox in 2018 and was put under Xbox Game Game Studios.

That might be the case, but it does not get any credits in most of their games.  Xbox Games Studios is US based and Playground Games is based in the UK.

Xbox Game Studios is a publishing arm under Xbox that included pretty much every studio Xbox owned not under Activision, Blizzard, or Bethesda. Lionhead Studios was under them before they were shut down a decade ago. Even Rare was under it until it was transferred to be under Activision today.

343i/Halo Studios finally losing Halo? About fucking time.

Lol, PC Gamer is getting roasted in the tweet comments for their latest article attacking Asha's Xbox changes today, love to see it.

They got far more chances than I would have given them. Halo 4 did well enough in spite of some controversy, but starting with 5 the series started to tank. 

Hopefully this new team Activision is building from the ground up is better. They need to find people who appreciate the original trilogy, but they also need a good multiplayer hook, because just same old, same old Halo multiplayer is not enticing to most modern shooter players.

Seems like Halo Studios was mired in cronyism right up until the very end, the guy who was promoted to Cinematic Director and fired one day apart was reportedly hired over better qualified candidates just because he was friends with the overall Art Director at Halo Studios.

Halo Studios really was terribly run. Such a shame. 

I am worried about The Coalition. I hope they aren't hit with major layoffs after Gears of War: E-Day launches. At least that games looks fantastic and a nice evolution for the franchise. Unlike Halo Campaign Evolved, which I did enjoy. But after beating it once and getting some more achievements it is unlikely I will go back to it.