Indeed, it appears that Blizzard has decided at the last minute not to send this reputation and experience granting item to players this year, after having put it in the game.
Given that a lot of players are still leveling up or gearing up for heroics and the Highmaul raid to be released next week, it’s perhaps not too surprising that Blizzard might not want to give players anything which would make it significantly easier.
But since the anniversary event is going on much, much longer this year than last year, I hold out a small bit of hope that it might show up later in December.
In the meantime, if you need a reputation bonus, Pilgrim’s Bounty is going on now. Note, however, that this holiday is not celebrated in Draenor, so you’ll have to return to Azeroth to partake of the bounty.