Mate.
We now have free to play accounts. We also have Classic - these guys at least pay, but they are playing a different game.
Most of all, this “best result in a decade” is on “engagement”. That’s not the number of unique players per month. That includes how often they login and how much time they spend. Yes, they got better at making people sit longer in their chairs, woohoo.
And for general perspective on MAUs, see this (they are declining):