2021 (real world)

June

 * June 29: The Art of Halo Infinite is set to launch, following its delay from a 2020 release.

November

 * November 15: Halo: Combat Evolved’s 20th anniversary

Unknown

 * Halo Infinite is set to launch, following a delay from its original release year of 2020.
 * Halo: The Television Series set to air.