It's not a joke. I am pretty serious about that.
Blizzard has said that we didn't see the last of N'Zoth... and the red thing that flew into Arbiter reminded me of the Emerald Nightmare.
It would make sense, N'Zoth/Void scheming to bring heroes to the realm of Death and let his minions(Alleria through the Turalyon) rule the Azeroth.
That's real 5D Chess played by an Old God.