Season 10

Season 10 was a planned season update for Halo: The Master Chief Collection, initially anticipated to release some time in 2021 but later delayed. As of December 2020, plans had been laid internally at 343 Industries for this season. Originally, Season 10 was the last planned season; the decision of whether or not to produce further seasons would have been made once Season 10 was completed.

In September 2021, 343 released an MCC Development Update in which they stated that Series 8: Mythic would be the last season released in 2021. In this blog, they also explained that with the release of Halo Infinite in December 2021, they expected the manner in which they delivered MCC content to change, pivoting away from large semi-regular seasonal updates and towards smaller ones that could be delivered as soon as they were ready, depending on development status and the studio's overall roadmap. The seasonal model within The Master Chief Collection was later shifted to series, marking the official cancellation of Season 9 and 10, with much of their content ultimately released in the Halo 20th anniversary event and the Series 9 update.

Intended content
Internal files within The Master Chief Collection provide some insight as to the content Season 10 was intended to contain. The file which tracks player unlocks,, retains old code comments that refer to Season 10 content, listing all of the Halo 2: Anniversary content ultimately implemented into the game with the Series 9 update. The content listed under these headings include;

Armor
A number of armor permutations for Halo 2: Anniversary multiplayer;
 * Breach attachments
 * Bioroid armor
 * Megaframe armor
 * Trooper armor
 * Panzerdoll armor

Skins

 * Black Tiger, Bloodscorched, Chrome Blue and Sandstorm weapon skins for the following weapons;
 * Assault Rifle
 * Battle Rifle
 * Rocket Launcher
 * Shotgun
 * Sniper Rifle