I think Crota's End should return as a 3-man dungeon tbh. It's about the length of a dungeon and was the only raid in D1 that was fully one-mannable. In order to make it achievable without cheesing, the bridge encounter could be altered to force you to cleanse the 'totems' by standing near them and clearing enemies. Once you cleanse both, then the Swordbearer knight spawns. Kill it, and power attack the plate with it to charge the bridge. You'll need to do this a few times to fully charge the bridge. Once done, you have to kill a bunch of enemies on the other side. Once you do that, you need to cleanse the totems on that side. Once you cleanse them, a Swordbearer spawns again, and once you kill it then the Gatekeeper spawns, kill him to move on to the 'Thrallway'. Or you know, they could change it however they wanted. Regardless, this Raid would require a TON of changes just to even make it on par with Eater of Worlds or Scourge of the Past which are already memed in D2 as being 'Strikes'. To make it a dungeon, it would only require changing that singular encounter to be solo-able without cheesing.