They have lives to lead? Vinny would have been the one to dive in but he has a kid and thus has ascended to a higher plane of existence.
Their jobs entail playing games, creating content, writing and doing videos, so yes, it's their job is to play popular things like this. Sure they have lives, but they also have a job. Personally I don't know why they haven't put a video out for it, but I'd guess they are assuming the people playing that game will get this regardless.
What do you expect them to cover? I'm not hating on WoW (I still play occasionally), but MoP is still WoW. It just has a different continent and new quests. There's nothing new enough to show that would really be worth it. At this point, people know whether they want to play WoW, so there actually isn't much reason to cover it, no matter how popular it is.
That's exactly what I said in the next sentence.
And you have two and a half other sentences making it sound like it's unreasonable of them, regardless.