It kinda remindes me of ES oblivion. Legion portals everywhere attacking the planet. And after we beat the demons we go to their world.
It is posible that we will have a scorge invasion like event (or elemental invasion) and after this some island rises from a sea and we use it as portal to another world (that is protected by azsharas nagas). Maybe a low lvl zone is somewhere is south seas and then we move to the legion planet.