I don’t know that you can say this at all.
For example, if you never want to never buy an automobile again, go to a fan forum that supports that make. If you read those posts, you’ll wonder why anyone, anywhere, buys a car at all with all of the horror stories laid out in full color.
As a “representative” set, the manufacturer makes nothing but lemons and works over time to cheat the buyer and consumer at every turn.
As always, there’s some deluded spokes-bot cheering the vendor on, but who listens to them anyway?
So, no, the only representative sample of the game is how much folks are playing and spending on it. This is a direct measurement of player “happiness” as a general value. Along with this they have to adjust for demographics, the economy, trends in entertainment, etc. etc.
Not only was the game different in the past, the world was different too. All of these account for game performance and player satisfaction.
The game content and experience alone are not exclusively responsible for the net subscriber rates. Lots of things factor in to this, and, no doubt, the analysts at Blizzard try to quantify and measure those factors so as to control (in order to boost success of the game, for assorted values of “success”) as much as they can.
So, anyway, I would not necessarily use the pulse of the forum as a measurement of anything, save for the pulse of the forums.