In this Video, there are some lines that Tyra Karn say regarding Siva. I think it would be awesome if Bungie gets the chance to bring back Siva into the Story and maybe have some new activity (similar to menagerie or sundial) on nessus to stop the siva outbreak there regarding the fallen and vex and cabal that are there. Maybe even bring back the strike that was originally gonna be in the game, or even just update the current ones to have siva in them. I hope they can do this in the future, but I wont be angry if they dont. Cheers!