No.

I think they got guidelines and are limited in what they can do with WoW's format.
Blizzard doesn't focus on storytelling in WoW. It's more a device to drive the dungeons and raids.

If the game had more focus on storytelling, like say FFXIV or Guild wars 2, the characters and their motivations could be better fleshed out.

When you gotta cramp it all in a couple of quests and an end of content cinematic, it's difficult to deliver that.