no one ever promised H&D2 co-op in a patch.
multiplayer modes are...
"objective" (two teams, one tries to complete objective while other tries to stop)
"Occupation" fighting over territory
and Deatmatch, you play as Axis or Allies
Co-op is included for new missions in Sabre Squadron.
not many play, but enough, it's not very realistic, more arcade, but good fun