Originally Posted by
Protar
So I'm of the belief that The Dark Below is indeed the next expansion. It clearly references the Old Gods, however the evidence for the next expansion being Legion themed is too much to ignore imo. It's practically confirmed that Turalyon and Allyria will be returning next xpac and I remember mentions of new Belf and Draenei lore. So logically we're looking at a conflict between the Old Gods and the Legion and I think the Rift of Aln ties into both nicely.
From the Old God perspective it's where Malfurion senses some great evil that is almost certainly N'zoth. As the Emerald Dream mirrors the real world it can be assumed the Rift exists on Azeroth as well, probably beneath the Maelstrom. It's a good candidate for Nya'lotha, with the Emerald Dream connection.
From the Legion perspective? Well as it happens the Dark Below is already a place in WoW. According to the Warcraft RPG the Dark Below is: "a place inhabited by demons, devils and infernal creatures, from where some sorcerers take their power directly and sometimes have a patron beast to foster their magic." Now the RPG isn't canon, but that exact name showing up in any relation to WoW previously is too much of a coincidence to ignore imo. And as it happens the Rift of Aln opens up onto the Twisting Nether; the perfect place for demons to make their way into the depths of Azeroth's oceans. If I were to make a guess, I'd say The Rift is the entry wound Sargeras made when he tried to force his way into Azeroth.
So, that's my guess: Not just the location of Nya'lotha and N'zoth but an open door for the Burning Legion to enter Azeroth. And I'm betting there's a raging conflict going on between the Old Gods and the Burning Legion. Afterall, the Old Gods feed on planets and the Legion destroys them. I'm guessing it's not a good idea to get in between the Old Gods and their food.