They've been playing a pretty big roll in a lot of expansions, and vanilla. They were a major presence in Cata, and now Legion. If anything the best their story has been is reflected in the Court of Farandis storyline, and it's barely about them.
I just don't see how continuing to include them as a major expansion force is interesting. Maybe an old god expansion Queen Asz can show up as a warm up raid boss and we can be done with them for good.