It depends on how they handle the money sinks in the game. We already have some in the game in the form of storage access (very tiny sink), repairing (varied sink), teleports. The best way is to have sinks in which the entire player base needs on a daily basis rather than having targeted sinks.
As long as there is a way to get players to spend money on high demand NPC items (potions, scrolls, materials, etc), that will be an effective sink as long as they’re not having to compete with players providing the same type of items. If players are able to market items on the AH, then there needs to be some kind of market fee to sink some of the money, otherwise the money just exchanges hands rather than being removed from the game world.
A previous MMO I played decided to go with a money vacuum rather than a sink by chasing after the 1%, or I should say it’s probably smaller than the 1% since there’s not that many players in the game. It was pretty terrible as many of the players couldn’t afford such things and it was a targeted sink (via crafting) so it only affected a small portion of players anyway. This was one of the reasons why I quit that game.