Well, the other bosses could always return. The Warpriest has his own Oversoul (Oculus), possibly meaning he has his own Throne World, and the Daughters are powerful enough to have their own Throne Worlds. Golgoroth is supposedly sustained by the Darkness itself, through the Tablets of Ruin, so that power might be able to bring him back. So if Oryx's lieutenants needs to be killed again, there's a point. Otherwise, no, the Raid is probably not, lore-wise, playable more than once.