While true, let's be mindful of the fact that Blizzard controls the amount of gold people could theoretically farm AND facilitates the trading of gold (enough to make a profit off of it while really not doing anything).
Yes, they've removed themselves from the step of actually buying it directly from them, however they could at any time change the amount of gold pumped into the game via quest rewards/loot drops. And while there has been times where the demand for WoW tokens outpaced the supply, we wouldn't really know if, say, a Blizzard exec or someone with vested interest could just create a character, generate some gold or WoW token out of thin air and simply make things available since we're not privy to such information other than what they'd tell us.
Not saying they would or are in fact doing this, but given that they have ultimate control over both supply and demand (it is their product after all), who's to say whether they have a hand in it or not?
I'd still refer to it as a bit of pay-to-win (or pay for advantage) but that's just because of the nature of the beast when it comes to dealing with tradable currency. Whether it's directly from Blizzard or from the players themselves, it includes a transaction of power with currency that's now purchasable for real life money.