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.
