I think it’s partially true?
It was pointed out earlier that after RWF they nerf almost everything in the raid.
That just seems to me, it is balanced around those guilds instead of around normies lol.
Not that normies would be ahead on that level anyway- they’re still in Heroic or pushing early Mythic bosses at the most, at that point.
I think a lot of content skews towards and is balanced around the best of players, regardless of pillar.
It’s often why some classes/specs remain in the dumpster, because Blizzard is afraid of what the pros will do with it.
League of Legends suffers the same problems- some champions have low winrates but Riot is afraid to tweak them, due to a pro that plays said champ.