WoW could use a "the story so far" as an optional cutscene where the main events are being shown and explained. It could just be a moving camera over and around places like the Illidan boss area, Icecrown, Dalaran, some scenery, some boss models and a narration.
It could be separated in chapters for each expansion. So a player is introduced to a loremaster npc/lexicon, could be someone of the Bronze Dragonflight and they got the option to learn about each chapter. About two minutes summary for each expansion leading to the current one will be plenty. Similar to how you can watch cutscenes by talking to npc's at the moment.