I'd love an Azshara expansion, particularly if she's raising up pieces of the seafloor to create new zones. Had some ideas about that myself.
Thal'Dranath may be cut, but there was a lot of speculation going on that it would be the tomb/prison of N'Zoth and that it would originally be underwater, only to be raised up from the depths by Azshara later on in the expansion after the events in Azsuna don't go the way she wanted. Hopefully that's what we wind up getting instead of night elf ruins. As far as something being way cooler than night elf ruins, Ny'alotha definitely qualifies.
If Azshara is raising up portions of the sunken seafloor, she could raise up Zandalar as well.