They probably keep WoW's warden way more up to date, though. All it does is searches open processes and injected shit for pre-determined file names/window names/process names to put it in simplest terms. They update a file on the servers which has a list of shit for Warden to look for, and if it finds any, you're banned.

Also, botting on WoW is much riskier, as you lose your account and you can't just make another one like in Diablo 2. You have to actually buy a new account, and you lose any play time you currently have bought. It's not really worth it in WoW.