The thing is, it’s known that people are more likely to take the trouble to post something they don’t like. They obviously like something about WoW, but forum is not full of, ‘I like xyz’ posts. Because anger is very motivating, and they see others complain, and so expect solidarity. You get some interesting replies when disagreeing with them 
Blizz’s difficult task is to sort genuine issues, from issues that going by forum are important, but in reality are not a sigificant complaint or is exagerated.
For example, lots of shard balance complaints. Yet in our survey, players feel outnumbered half the time or less. That’s what I would expect based on my own experience. When someone is annoyed, and wants agreement, very tempting for them to exagerate. Blizz have the actual data, they know the score, and I suspect it’s not far off our survey results.
I doubt WM will significantly change in 9.0. It doesn’t need to, therefore why put dev effort into that. If they can add more to it, mix it up a bit for 9.0, I’m all for that tho.