Or Blizzard could just say "Hey if someone random sends you a huge amount of gold, don't accept it, report it", alternatively, you could report it if you take the gold by accident.
After all, if you receive a huge amount of gold from a random person, you can guess that something odd was happening.
Then Blizzard deletes the gold off your account and you're fine.
Even if you want to disregard that, there must still be a middle ground between "We ban everyone that looks suspicious" and "Well, we can't do anything, sorry guys".
First off, on chinese servers boosts have so common that it's difficult to avoid them and there those boosters have even taken aggresive steps to bully people out of a group in order to make room for their boosters.
Here's a link to that:
https://www.wowhead.com/news=316097....in-chinese-wow
Also, check the gif in that post in comparison what is happening in the video linked in the OP.
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