I'm wondering the same thing. This is annoying as hell. I woke up early and plan to play this all day. It's going to be a pain in the ass to have to redo a ton of stuff because Microsoft are too damn lazy to get their asses in gear and have the achievements Live for their new release games. I've literally never had this issue on the One before. Figures it would be on the game I've been anticipating playing the most this year.
UPDATE: I just popped an achievement in the game, but it isn't showing in the achievements list. I did get credit for the gamerscore though. So weird. Hopefully this is in the process of being fixed and will be resolved in the morning.