John Hight, Warcraft’s senior vice president and general manager, spends more time thinking about adding value to the subscription than asking for more money. “As of yesterday, we have three games you can play under the same subscription, which hasn’t changed in price in over 20 years,” he told PC Gamer in an interview at GDC. “Take that, inflation.”
Hight says a price increase "gets brought up during discussions from time to time," but points to things like WoW Tokens—items players buy for in-game currency that convert to game time—and regional price adjustments, like in [Australia] as examples of Blizzard trying to work around it.