The next update for Halo 5: Guardians, Memories of Reach, will be available tomorrow – May 12th, 2016. The update adds Infection game type, Noble Team armor sets, Brute Plasma Rifle, Jorge’s Chaingun, and the Phaeton Helios to Halo 5.
Memories of Reach is the second to last free content update detailed for Halo 5: Guardians. The next and presumably final content update is Hog Wild. Hog Wild is assumed to release in June. Warzone Firefight’s release date is TBA.