I dont play much, in fact I just started to play again. I had got to lvl. 7 then quit. The Blades were kinda fun and interesting, but remember, Crota has been killed, whether you have TDB or not. Since he has been bumped off, so have the blades. The wolves will follow. Whatever Taken roam around will probably "disappear" when next dlc after taken king drops. Maybe the last dlc will have the darkness itself and it somehow revives all of the evil ones. Maybe it would involge a massive war. But it is unlikely that would happen. I assume each race will loose their dlc characters whenever the next dlc comes out