Halo: Reach will support co-operative campaign matchmaking, you just havenât seen the feature yet because Bungie doesnât want people getting the story spoiled on the first mission they play.
https://lastchance.cc/halo-reach-to-support-campaign-matchmaking-5618929%3C/a%3E%3C/p%3E
That said, the potential for spoilers still exists if you hook up with a more advanced team. Missions may be vetoed like any map in standard multiplayer, but if the majority overrules your desire to play a part of the campaign well ahead of your singleplayer progress, youâll have no choice to bail out before it begins.
In summary, âIf youâre worried about spoilers make sure you finish campaign before jumping into this playlist!â Bungie writes.
No specific date was given, just âearly October.â
Bungie Weekly Update 9.17.10 [Bungie]
