We have "Daily Story Missions" - though without ALL the quest/story missions and not on a good RNG rotation.
We have the "Heroic Strike Playlist" - and get locked out from the normal Strike list if we bought the DLC.
We have a selection of Nightfalls every week.
We have 'rotating Crucible and Gambit maps' - and soon to have G. Prime maps on rotation as well.
But we don't have a "Heroic Adventure Playlist" yet!
Imagine - Load up the playlist - maybe have it be 30 light lower than the Strike playlist - enable matchmaking for up to 3 players - add the global modifiers - maybe some of the unique ones from Y1 that rarely show up anymore - and have milestones for 1 and 5 completed? Maybe even put a rare reward in the loot pool (a la Otherside)? I'd definitely play them.