It just so happens that I have an old/throwaway Hunter alt that looted the Warglaives of Azzinoth a few years back. Recently with the Korrak’s Revenge thing I leveled up a throwaway DH alt.
How come I can’t transmog my weapons to the Warglaives of Azzinoth on my new DH?
Edit: oh, complete BT timewalking when it comes up, and then you’ll be able to.
Double edit: nevermind. I’m pretty sure you have to actually equip both glaives before you can begin the journey to get them as a mog on your DH, so having them on a hunter will do… nothing for you unfortunately
Hunters can’t equip both of them, iirc. And you need the achiev from equipping both, plus you need to kill Illidan in BT Timewalking for that achiev in order to unlock the transmog for your DH.
Is that for real?? So I have to re-grind the Warglaives, and equip them, just to be able to transmog on my DH? Lame… 
You need the achievement for them along with time walking bt.
THEN do Black Temple timewalking to get the cosmetic that allows for DH to use the appearance for transmog.
I am VERY salty because my Demon Hunter has the actual Warglaives but not the cosmetic from BT Timewalking, so no Azzinoth transmog for me until I actually get the nerve to do BT Timewalking.
It is very easy slightly below a normal and just a touch above a lfr.
That said the fact it is only available 2-3 times a year is a pain.
just to flex a lil bit:
dropped the off hand 3 weeks ago and on the next week i dropped the main hand
Statement: demon hunters can only use them if they complete the achievement in timewalking BT