I don't remember what mission it was... but in Taken King one of the quests you intercept a Cabal message meant for the head of their Empire.... since it's almost certainly Cabal themed we can assume the Emperor of the Cabal is coming - probably for Oryx (Revenge for Phobos and Skyburners), but he's going to find out Oryx is dead and mess with us for some other stupid reason. Earlier in the game we learned the Cabal were fleeing from something - we still don't have a definitive answer as to what -but it's safe to assume that since we find this out pre-Crota death, that it can't be/most likely isn't Oryx and the taken. Basically they will probably use this to set up a new super enemy faction to lead into Destiny 2, whatever chased all the other factions into the origin systems along with the traveler. Then we're going to find out that the Traveler IS the Forge of the Gods and the Cabal needed it to fight whatever crap this was coming for us. Capable of creating, weapons, light, ghosts, preserving life, terraforming planets. It literally is the Forge of God. Calling it now.