Classic has given Blizzard it largest quarterly increase in WoW subscriptions in 15 years.https://www.gamasutra.com/view/news/353605/CoD_and_WoW_push_Activision_Blizzard_to_betterthanexpected_Q3.phphttps://investor.activision.com/news-releases/news-release-details/activision-blizzard-announces-second-quarter-2019-financial
Just think this subscription increase beat Wrath of the Lich King expansion. The number of people who subscribed for classic beat all the previous expansions. Makes one think. Take into account that retail subs can be paid for with tokens and classic does not allow that.