In the mission, Outbound Signal, we learn that the Cabal Emperor knows that there are no more high-ranking Cabal officials in our system. The most prominent guess for Destiny 2 is that the Cabal will invade our system. This would mean war.
If you have read the Book of Sorrows, you should know that the three Hive gods (Oryx, Savathûn, Xivu Arath) all created Throne Worlds, which are "guarded" by courts (as seen in the Court of Oryx). It says in the Book of Sorrows that Xivu Arath's court is wherever there is war.
Now, here is where the speculation begins. If the Cabal invade our system, could they bring a big enough war to where Xivu Arath's court, and Xivu Arath show up (maybe as a dlc)? Anyway, leave your thoughts below!
I'd like the out bound signal bringing the cabal emperor, but instead of the hive they cause the vex to retaliate, then later when people get they're fun with them. Then we can bring in another hive god, with a short story like what they did with rise of iron except this power comes from this new hive god.