halo 4 D.L.C.

So where did all the DLC playlists go?

There’s no dlc playlists right now. The last one ran out on sunday. Maybe they’ll do another dlc playlist in the future.
You have to go into a playlist that has dlc maps, with a full party, that all has dlc. Then you have to get a dlc map and vote for it. Then you can get your achievements.
Hope that helps.