Those layoffs are certainly sad and angering. As someone who was the victim of mass layoffs in the past, I can relate to anyone affected.
I hope MS is better on this than my last job though, I got laid off with 0 compensation 2 days prior to a holiday so they didn't have to compensate me for the said holiday.

As for what it means for MS and Xbox projects I'll wait until the dust has settled and we know exactly the extent of those in affected studios.
for now, I assume most affected are from Hololens, edge, and marketing divisions with only a few dozen hitting the Xbox divisions. It may look like MS decided to axe the next campaign for Halo but doubt it because I would think that if it were the case they would have bundled this announcement with the layoffs ones.

I'd be surprised if they'll share a similar horror story.  Severance packages have to be a commonality for them.

Yeah...I don't think it changes much for Xbox's release schedule, as the hiring freeze was mostly lifted, never on Zenimax in the first place, despite all these layoffs, Zenimax is still hiring a near hundred employees and even though they were hit, it was mostly marketing and producer roles which in a awful way, Microsoft probably sees as replaceable or unneeded.

It looks like 343 took the absolute blunt of the layoffs, a lot of senior staff and mostly developers. Microsoft probably in the shittiest way possible saw the marketing roles as redundancies and decided to combine some of them and games tend to have dozens of Producers. I think 343 is incredibly poor timing, a combination of Infinite underperforming, 343's fuck ups and a change in direction makes them an easy target for Microsoft.

Unsure what it means for 343 now, the Campaign team was hammered, the MP/Forge team seems safe, I think the expansion plan is dead, I don't know what it means for future Halo Campaigns though, if they're going to change direction and go back to a more traditional release or what, I think they'll double down on Multiplayer for now and we'll see what their plans are for Campaign stories.

There are rumours that 343 is going to focus on MP whilst at the same time doubling down on being a sort of publishing house, like World's Edge, and they'll instead hand the Halo IP out to other studios and let them tell stories, I actually said one time that Microsoft should do something similar but in reverse, that Certain Affinity should take control of the MP and 343 should focus on the Campaign.

Guess if true, Microsoft wants the internal studio focused on the money maker. They'll no doubt be a "next Campaign" but question is what form it takes, a more traditional release from 343? From an outside studio? Does the F2P MP get revamped once the next Campaign releases? Will the F2P MP be entirely detached from the next Campaign? Will they stick with Slipspace for the Campaign? What if F2P BR takes off? Do they go back to a traditional MP release as well?

So many questions. Idk which is the best approach but I will say if the rumour that they might hand the IP out to external studios is true, I doubt companies want to work on Slipspace, they'll either want to work on their own engine or Unreal Engine. So if they're unwilling to do that, maybe 343 just takes a break on the Campaign whilst they slowly restructure.

Pierre is brand new leadership as well and proven himself with TMCC so I'll give him a chance, it could well be partly his decision to restructure the IP as well. No matter what I think we're waiting years for the next mainline Halo story, they'll starting from scratch.

But these layoffs fucking suck and are just sad, depressing shit, and definitely not the end of things.

FWIW.

Laid-off workers will receive 60 days' notice, six months' health care coverage and stock vesting and "above-market severance pay," Microsoft said.

I don’t want to sound too harsh on 343 but I am honestly not sure what other outcome could have been expected after the last 10 years. Despite getting the most money they have been the weak link in XGS, and if they had not been attached to Microsoft the studio probably would have been shuttered years ago.

At some point there are consequences for producing sub par work. I know it largely wasn’t the fault of the devs, but after Bonnie Ross was forced out the writing was on the wall.

If 343 does double down on publishing, it doesn't sound too bad of an idea, I've been demanding for years that 343 takes advantage of the IP and does a lot more quality spinoffs. Seeing other studios take on Halo's world will be interesting, in multiple different genres. But I worry what it means for mainline Halo...Maybe they will just outsource the development to another studio but stay in control of the story/creative, like The Initiative.

343 will significantly downsize in this case whilst focusing on Halo Infinite's MP with Certain Affinity but still retain a story/creative leadership team, like how Halo Wars 2 was done by Creative Assembly but the writing/art direction was done by 343...Perhaps we may see something like that expand to the mainline Halo stories.

This is correct since I was a contractor at MS during that time when they lost a lawsuit concerning having contractors for decades without paying benefits.  During that time, MS released all of their contractors when they lost that lawsuit and then after a year tried to hire them all back.  I am sure many declined like I did because I was not going to be put in that situation again.  For certain contractors if you are going through an agency, they provide benefits which gets around this issue but if you are independant which is probably more for gamer developers and content creators they fall into that benefits issue.

I was going to say that MS severance package are pretty good so these people if they get a job quick will have a nice sum of money in their pocket.  I was layed off of a job and got a nice severance and was in a new job before the end of the month I was let go.  It turned out that it was actually pretty damn good situation.  I doubt it will be for everyone but for some they will probably come out much better than where they were before.

I see 2 possible scenarios here for 343/Halo:

1. The next mainline Halo is going into pre-production, and Halo Infinite is no longer planned to get 10 years of support (2021-2031). Most or all singleplayer DLC for Infinite has been canceled, and multiplayer support for Infinite will continue until maybe a year before the next mainline Halo releases, release probably around Holiday 2026-Holiday 2027 for the next mainline Halo. Because only the Halo singleplayer concept and writing folks are needed right now in the preproduction phase of the next mainline Halo, Xbox decided to layoff most of the rest of the Halo singleplayer team to save money in the meantime since they are no longer needed to develop the cancelled Infinite singleplayer DLC, and will start to staff the singleplayer team back up once the next mainline Halo enters full production probably later this year.

2. Halo Infinite 10 year plan is staying in place, but will now be multiplayer only. 343 is done with developing their own singleplayer Halo content, they will keep a small-mid sized team of writers, concept artists, and franchise managers at 343 who will be assisting 2nd party partner studios with developing singleplayer Halo games moving forward. 343's singleplayer team will basically be using the same development model that The Initiative uses, alot of lead positions at 343 with some leads and all of the grunt work at their 2nd party partner studios. 

This yeah, much better articulated than me. These are the only two scenarios I see.

It's either a rescope, refocus and come back later or they're outsourcing it.

Still a lot of questions even with those two scenarios though.

1. Will Infinite F2P MP end at some point and if it does, will it simply be replaced by another F2P MP (like Overwatch 2).
2. Will the next Halo Campaign be entirely detached from the MP?
3. If 343 does outsource it instead, whilst leading creatively, will 2nd parties really want to work on Slipspace?
4. Does Halo Campaign need to be Slipspace if MP/Forge are separated? Is it ideal to have MP/Forge on Slipspace but Campaign on another engine?
5. If they stick with Slipspace, do they attempt another revamp of the engine?