We will have to see what really happens to N'Zoth and Azshara after 8.3, but at the moment, it very much looks like at least the former is offed in a really anticlimactic way.
And if characters people were hyped for for years really get tossed to the wayside like that, why should I care about a bunch of death-related enemies they wanked out for specifically this expansion?
Again, I'll just wait and see, but for now, it doesn't look good to me.