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 10 (Halo Wars 2).
Season 10 is a planned upcoming season 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 is completed.
In September 2021, 343 released an MCC Development Update in which they stated that Season 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 impact this will have on Season 10 and its planned content is currently unknown, with 343 promising elaboration in early 2022.