Halo 360 services are going offline in December 2021

[Deleted User]

At the end of next year, 343 Industries will be turning off the aging back end legacy services that power some Halo Xbox 360 game features.
While these games will still be playable, features and experiences that require online services will be reduced or disabled.
The Halo titles within MCC have been rebuilt and remastered to leverage totally different, modernized services and will not be affected by this sunsetting.
Also Halo Wars: DE (on Xbox One and PC) will not be impacted by the Xbox 360 services sunsetting.

The following Halo Xbox 360 titles will be impacted when we sunset online services late next year: 

• Halo: Reach 
• Halo 4 
• Halo 3 
• Halo 3: ODST 
• Halo: Combat Evolved Anniversary 
• Spartan Assault 
• Halo Wars 

Source:https://www.halowaypoint.com/en-us/news/sunsetting-halo-xbox-360-game-services-in-2021