I'd say no, I believe it'll be the big story driving Destiny 2. Vex are neutered, Fallen are scattered and Hive have been debased. Cabal on Mars are still not getting anywhere but doubt their command would accept defeat and ask for help. My guess is a rogue Cabal sent the signal, and reinforcements are coming. Could be a little civil war in there. Either way I believe that will be the main focus of D2, with DLC's featuring off-cut stories in the same manner as Destiny 1. Also there is a tiny team left on D1 right now with the main workforce on D2. They pulled some help for RoI but I imagine they're back to their Skeleton crew again. We may get some rehashed year-1 raids as Bungie seems to be giving us everything we want right now but that'll be it. Not a lot of effort to move some confluxes around alter some enemy spawns.