There are plenty of people calling it a WOW killer, including several high profile streamers, including Kungen from Nihilum which for those familiar with vanilla WOW pretty much dominated world firsts for several years.
Wouldn't pay any attention to Kungen, he only goes where he thinks the stream money is.
Played WoW, slated it, came back as thats where money was, then left again. Slated LoL almost daily, went there as thought would make him money.
It'll be the same for WS, he'll disappear once his viewers decline.