Cabal invasion might be a start but the hive are almost finished all the top rank characters are now dead but the fallen from the plaguelands might pose as a threat if the hive in the cosmodrome suddenly disappears from the area and the spices decide to turn on house devils & house kings that only leaves the taken which share the same fate as the hive so that means that leaves a vacuum for a new enemy to rise up.
I don't think so, I mean with the main SIVA core destroyed the splicers are done. I'm hoping D2 stats off with us on a massive campaign to wipe out the kings which would likely take us to the European Deadzone, and then from there the Cabal invasion should have a chance of hitting us by surprise. But saying he Hive is hurting is wrong, the Hive in are solar system sure but you still have 2 Hive gods who most likely have huge fleets of their own.