From Halopedia, the Halo wiki
This article is about the content update released for Halo: The Master Chief Collection. For the seasonal update for Halo Wars 2, see Season 9 (Halo Wars 2).
Season 9 is a planned upcoming season for Halo: The Master Chief Collection, originally anticipated to release some time in 2021 but later pushed back to 2022. As of December 2020, plans had been laid internally at 343 Industries for this season.
In September 2021, 343 released an MCC Development Update in which they stated that Season 8 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 impact this will have on Season 9 and its planned content is currently unknown, with 343 promising elaboration in early 2022.