Not to mention the sick cinematics that Blizzard is renowned for. Definitely not 'maintenance' work. Patches for WoW – maybe – but expansions are huge effort!

Not to mention the sick cinematics that Blizzard is renowned for. Definitely not 'maintenance' work. Patches for WoW – maybe – but expansions are huge effort! Not to mention Blizzard aim for global simultaneous release for its games whenever it can. (Asia used to lag behind WoW's expansion up to a whole year compared to NA/Europe) Can't imagine the effort and coordination required for that task.