I really liked waht I saw of these two groups in Legion, even though they took very heavy hits.. but hte Warden Vault, the whole theme, and the Moonguard too with their stronghold - it would be nice to see an in game legendary strong night elf mage group, and to see more of the wardens doing good.
Tbh, I didn't like that they kept turning the Wardens evil, Cordanna, then Sira, tha'ts not really the type of lore I want. I also want to see more Illidari stuff now also and more of the Farondis kind of Highborne.
Interesting how good a lot of the lore of Legion was, the detail was phenomenal (for Wow), and how totally underused or misued it has been since then.