The evidence has been discussed multiple times in this thread by multiple posters. There's no need to go over it again.
When I said "launch" I was talking about vanilla WoW.Blizzard did not implement undermine at launch because undermine it's not a location we'll explore in the first arc of the story.
And Blizzard has repeatedly pulled from that non-canon source for WoW content.A source that is non-canon, I'll remind you.
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Yeah, I don't believe that's going to be the storyline. I believe the storyline is more about us taking down Gallywix not to save Undermine, but to essentially stop him from doing nefarious things that could lead to a bigger problem. Whether that's damaging the world soul, releasing a void creature, corrupting a titan device, etc.
I don't think Blizzard wants to remove the corrupt cartel flavor from the Goblins. Unlike Xal's influence on the Nerubians, the corrupt cartels are a feature of Goblin civilization, not a bug.