No first you have to point to credible villans or ones being worked on. Instead of working on a new major villan legion is building azshara nzoth the ethereals and the void
We have azuna and the tidestone
We have nzoths emerald nightmare
We have the lore goldmine shadowpriest dagger
We have all sources implying nzoths prison is below ToS
We have the emeral nightmare boss quotes
We have magni waking up and talking to azeroth
We have naga even in the ToS raid as bosses
We hve the huge void presence on Argus
We have a ethernum and void themed dungeon in 7.3
We have the titans telling us to product azeroth in the mined 7.3 finale quotes
We have kul tiras mined stuff which is in proxomity to nazjatar and nzoths prison
Nzoth and azshara reside in the last unexplored islands dotting central azeroth and below