The Exo Stranger is Taox!!! Or Taox is still inside the Traveler and will be come out in future dlc where we either deal with the "Worm God" or maybe vex again since if the Stranger is Taox she seems to be more worried about the vex than give now. Especially since we killed oryx the leader of the hive. But also where are his sisters? They might want revenge (if still alive, don't have all pages unlocked) but apparently aren't as strong as oryx but still immortal unless killed in their throne rooms.