I heard The War Within, and the trilogy thing are actually all part of Blizzard’s ploy to cover up their real expansion. I heard it’s actually called Gnomekind Divided. It’s about the Mechagnomes struggling to fit into the organic Gnome society, being persecuted by the organic Gnomes, while we discover Mekkatorque is actually part of a group called Il-Gnomenati that is controlling the whole Azeroth, and we have to stop him from merging with the AI GNoME in his attempt to become a Titan.
Maybe some gnome influence on the story. Xal’atath knows the Manastorms (which have actually posed a threat to Azeroth ages ago) and the Earthen were created by Mimiron. 
As long as I get to kill gnomes, I’m down.
If they announced a gnome expansion it might actually be enough to get me to not buy a WoW expansion.