It has been long rumored that Certain Affinity was working on an unannounced Halo Battle Royale title that went by the name “Project Tatanka”. This game was reported in 2022 that this project would potentially be a PvPvE-like experience that would aim to attract fans of Fortnite, Call of Duty Warzone, and Apex Legends.
According to Shpeshal Nick from the XboxEra Podcast, Project Tatanka has been completely canceled. This comes from his sources and others have heard the same thing. The project started off by being a battle royale mode for Halo Infinite developed in Unreal Engine 5, but it had “evolved into something more” during its development.
You can see the timestamp on YouTube below where Nick talks about this project:
Certain Affinity has been known for working on smaller projects for Halo like Map Packs in the past for Halo: Reach and Halo 4. It seems we will never know officially what Tatanka was going to be, but many would say Halo has the perfect universe for a Battle Royale.
Thanks, Reddit for noticing this.