Indubitably true. They know better than any random poster. Most random mouth-breathers can barely create CO2 from O2.
They do not know better than a consensus of many players. When you have threads 100 pages long on the beta forums complaining about, say, Azerite armor, or legendary acquisition, or Torghast sucking, that should be treated deadly seriously and not discarded, even if it means you need to redesign systems or build new content that could delay release. I've been in pretty much every WoW beta since WotLK and quite a few alphas and EVERY single time, if there's a 100 page thread that isn't addressed, they have to go back in patch X.1 and X.2 and do their best to fix it after the fact. The devs were never right, the players in those threads were always proven correct. But by then the damage was done.
Organized feedback must be considered, even when or even particularly when it's consistently negative. Which it usually is, because who's writing super passionate screeds about a feature they enjoy? They just play it. Anyway not doing so has been their failing for this entire post-Ghostcrawler generation of WoW developers. GC wasn't perfect and I disagreed with many of his decisions, but you could talk to the guy.