There seems to be a mismatch, or poor definition of canon when people apply it to world of warcraft.
Are the books canon?
Are the cinematics canon?
Is something automatically canon if it is in-game?
Does a clash between gameplay and story restrictions make it not canon?
Do you consider tooltip descriptions canon?
Etc.
So what do you consider part of canon?
(sorry, I had to)
It’s actually a valid point, tbf. i’ve heard that the gadgetzan shown in the hearthstone trailer is more representative of “canon” gadgetzan than the one you can currently visit in world of warcraft.
Generally its whatever the writers say at any given time and the game tends to bend the rules a bit to make for a more fun video game. Theres really no hard line that says whats officially canon or not unless writers explicitly say so and even thats subject to change.
The way i see it, what happens in game is more or less a broad strokes version of whats happening. Like say how a group of adventurers took down balakar khan after staving off the nokhuds allies is canon but the 15 minutes we spent crashing into everything and dying isnt canon.
Opinions vary, but the very best cannons generally come from Krupp, Rheinmetall, and Oerlikon.
Some.
Some.
Sometimes.
Sometimes.
Sometimes.
Sometimes.
Some things.
The distinction between canon and non-canon in the Warcraft universe is pretty much nonexistent as Blizzard continuously rewrites previous history as they decided to change established rules and lore. At this point I decide what is canon and non-canon for myself and don’t care what this new guard says.
OP, the answer to your question is this…
EVERYTHING post Wrath is fan-fiction.
Everyone knows that.
I’ve heard takes identifying anything past classic as fanfic 
My more serious answer is that I don’t have a perfect answer to the question. As a player with my own silent RP churning in my head as I play, I don’t think in terms of “canon”, I think in terms of “what have my characters seen, heard or read and how much to they trust all these different sources”
I still remember the time when I saw videos of people killing Illidan on youtube and how awesome and epic it used to be…
And the youtube comments that were like “so you killed Illidan, big deal who cares”
This is a fair way to interpret it, as specifically thinking in terms of canon is probably more of an ooc exercise overall.
another good one
None of them. WoW is now in “Make it up as we go” mode.
WoW in the late 2010s and early 2020’s is a reflection of where our culture is at, there are simple rules you have to follow…
1-You have to have as many female characters standing out as possible.
2-If a female does bad unforgivable things like Sylvanas, you have to give her a redemption story.
3-On no account is a woman allowed to be saved by a man, even in the recent Super Mario movie, Princess Peach was shown to be much more kick-butt than what I remember as a kid, and freed herself n the end.
4-Dragonflight has stood true to the tradition of portraying men as buffoons, with Alextrasza as a woman showing that she is the adult by having to step in and tell Wraithion and Sabellion to sort out their own crap.
All that matters is that females are in charge and the adults these days.
This camera is canon
aw, that’s kinda disappointing
Even the dev team sometimes forget canon.
Reminds me of the tale of the Red Shirt Guy…
Books? Yes.
Cinematics? Yes.
Is something automatically canon if it is in game? Yes? Maybe? What?
Between gameplay and story restrictions, gameplay should win every time. Function over form. Not really sure how this impacts canon.
Tooltip descriptions canon? Maybe? Depends on the tooltip. Most of them are purely functional, but something like Wraith Walk “the death knight walks through the shadowlands” sure. Why not?
Most people that complain about lore, or retcons, or canon are incapable or refuse to acknowledge that time moves forward. Things can change. Just because something WAS true, doesn’t mean it has to remain true. Characters can lie, characters can be wrong, characters can be manipulated. Details of an event can remain unknown, for years, or even indefinitely.
BfA and Shadowlands aren’t canon.
The patch notes in which Draenei can become Warlocks are cannon.