Thing is in 8.0 and 8.1 it was much more about what you mentioned, but with 8.1.5 and onwards it split. In game it became mostly about Azshara and Nzoth, while Sylvanas and Saurfang got its major story moments in the form of CGI cinematics. they were connected to some quests but the meat happened in the videos and you don't lose much by just watching the short movie they made with the CGI stuff