At first glance, the plot of WOW's Legion expansion is clear indication that Blizzard have indeed run out of ideas story-wise, on account of how it harkens back to the Burning Crusade, the first expansion of the game, which also features the Burning Legion as its main antagonist. At a closer inspection though, as one gets more immersed into the new content, it becomes obvious that Legion is not at all about recycling, but rather about making superbly great use of the rich and abundant lore built up over the massive lifespan of the IP.

The accent on the social aspect is obvious from the get-go in Legion: players are grouped into two massive armies, one representing the alliance and the other the horde, to try to stop the onslaught of the world-conquering demons. At one point in the game, the two factions are separated by a chasm, and for some reason, they take turns fighting the invaders. Needless to say that such an approach results in the defeat of all Azerothian forces, as the leaders of both factions are slain. Interestingly, the killing off of these characters makes perfect sense when players are required to step up to the plate and fill their shoes. In fact, players end up leading their chosen character-class, which means that a powerful incentive is implemented to level up several characters, just to experience all the different quest-chains.
The garrison system introduced by the Mists of Pandaria expansion has been overhauled as well. Now, there are class halls...