My personal thoughts? He’s off learning to play the organ.
Stuck on page 110 of the mage guide to the universe.
He’s trying to get into Mythic Antorus mog runs, so don’t expect to see him for at least one more expansion.
Hopefully not coming back. He was so boring and always showed up with a new grind.
Would rather have Khadgar over Genn Greymane, Sylvanas, Anduin, Thrall, Jaina - the list goes on.
I read that as “always showed up with a new girlfriend”. And I was like “PSSH yeah, that kind of guy”.
He looked forward in time, to view alternate futures, and see all the possible outcomes of the coming conflict against the Jailer… how many did he see? 14,000,605… how many did we win?
…
…
“ONE…”
Oh god, Captain Marv - Med’an…
I saw him with Modera…
In an art…
My guess is that he’s studying how to close portals after his last dozen attempts failed.
Archmage Khadgar yells: OW! What in the light was that?
Archmage Modera says: Khadgar, what’s wrong? What happened?
Archmage Khadgar says: Something… bit my head I think.
Archmage Modera says: Something bit your head? That’s all? Would you like me to kiss it for you?
/kiss
Still looking for his golden coins on the broken shore. Why does he need them? Never you mind why.
I’m still waiting for the head in the crystal ball to arrive in Oribos
No… Captain Illidan, after he flies through the “Finish Your Run and Exit Torghast” screen, which was raining down soul blasts on everyone until he destroyed it!
Thrall: “Illidan, you’ve returned! We could use your assistance!”
Illidan: “Hello there Tyrande, do you have something for me?”
Tyrande: “I don’t know how you’re getting through all that…”
Prince Renathal: “Don’t worry…”
Baine: “He’s got help…”
Every male in Warcraft rallies to Illidan as he then single-handedly scorches every Mawsworn in his path to ashes with one god-tier Fel Rush
H-hi my name is Tyrande Whisperwind. 
Hey Tyrande, you got something for me? 
Idk, but he better come back. His puns were off the charts.
That dirty traitor is sulking on kharazan, he went to hide his head under a rock when he heard there was another war.
If you are seriously curious, he is in Karazhan researching how to help heal Azeroth. He is very disappointed in the Horde and the Alliance going to war with each other after Legion.
Flynn and Shaw stopped in on him recently.
His crow form is Find Pepe
he’s still doing an audit of the 4985 apexis i brought him six years ago
and maybe growing back his beard