During the great THQ fallout of 2013, You Don't Know Jack
was one of the games caught up in the mess. After it failed to be sold in the first auction of THQ's assets, Nordic Games picked up the rights to the franchise in the second auction as part of a massive package deal. Up until now, the game and its DLC content had managed to hold onto its grasp on the Xbox Games Store and had remained on sale. I say "until now" because the game and its four DLC packs have now been removed from the Games Store.
While a hard copy of the game can still be purchased from retailers, the DLC is now gone for good unless Nordic Games decides to republish the content. If we get any news on the possibility of this, we'll be sure to let you know.