... No clue what the guy will do at Xbox publishing besides being another cog in the wheel.
Staten has worked in Xbox Publishing before. He's basically been Microsoft's fixer for a while now, usually brought in to make the toughest decisions. He wasn't brought into 343i because he had history with Halo, that was largely coincidence. 343i couldn't ship a fucking game, so Staten came in and got it shipped for better or for worse. He's a closer, and he closed. Job done, time to go.
So the creative head of a failed studio is now going to join Xbox Publishing...
See above.
As for the layoffs, 343i is Microsoft's largest studio. They're also their worst studio, with the worst output by a wide margin. If any company in Microsoft's stable needed a cull, it's this one. How they can be this large, take this long to make games, and deliver quality this low is shocking. Their CEO was fired for a reason. This feels like house cleaning, because clearly, people aren't doing their jobs.