Give it a watch. Its Jason Schreier and not just some random numbnut.
But tl;dw:
Eg Obsidian and other MS studios use codevelopers. Which could be an assetmill in east asia or fucking Eidos Montreal which develops nearly an entire game under the supervision of a few employees of the "main" studio. All these studios feel the rippling effects of closed projects and entire studios, too. With that even more hidden lay offs.
But MS also uses "vendors" which are basically sub contractors. So they might not have an @xbox.com work email. But they work fulltime on the xbox campus with or among all the other official employees but arent employed by Xbox/MS. Xbox cut vendor spending by 50%(!).