TBC was the first time they really ‘messed up’ and it was only really the Draenei, who we knew as Broken beforehand, were retconned to be a non-barbaric race. We knew them as swamp-dwelling hermits.
Aside from that one thing, I don’t recall people hating the lore that much.
Alliance players mad they didn’t get elves, and that was basically the biggest outrage at the time.
Yeah, the lore was ‘muddled’ but it was certainly serviceable. It wasn’t like people outright rejected the narrative as was the case with BfA and SL.
People still played TBC and enjoyed it, even with the lore problems.
Blizzard learned they can’t kill their own villains two fast. Literally everyone (the raid bosses) in TBC came back.
Kael came back three times. Illidan, twice.
Even Gruul we saw again in WoD.
Blackhand too, and other ex-fel Orcs.
Magtheridon in Legion, Kazzak, and so-on and so-forth.
They’re still reaching back into TBC for lore, even today. We’re getting Man’ari which first appeared in TBC, and they are constantly adding new demon/warlock lore.
If we ever get a light/void expansion, I have no doubts Outland will somehow be involved- maybe as a starting point for a space-faring expansion. Same as how we use EK/Kalimdor for boats to take us to newer continents.
The Sunwell will also likely be involved, if the Void Elves are anything to go by.
There’s still a lot of rich lore in that area is what I’m saying, and that expansion was over a long time ago. The same is true for Northrend.