You might not want to count on playing Xbox 360 Halo games online for much longer. Thurrott reports Microsoft and 343 Industries are winding down Halo Xbox 360 services over the next year. The two have halted digital sales of all Halo games for the platform (DLC is still available), and will shut down matchmaking, challenges and other key online features for the titles “no sooner than” December 18th, 2021.
This doesn’t affect Master Chief Collection games or Halo Wars: Definitive Edition, but it does include the backwards-compatible versions you play on the Xbox One or Series X/S. The Xbox 360 versions will still support custom online games, local games and online squads — you just can’t use features that depend on services.