According to Coming Soon, Star Wars: Battlefront will be a lead-in to the Force Awakens, giving gamers and movie-goers something to chew on as far as Star Wars lore and continuity goes. The game will feature the Battle of Jakku in a DLC pack, which will be available as a pre-order bonus on December 1st. According to EA, the DLC will explain how the giant Star Destroyer ended up buried in the sand of Jakku.
Don't worry, though, the Battle of Jakku DLC will be available to everyone, for free, starting December 8th, 2015.
According to Coming Soon, this is the official description for the pre-order DLC:
the pivotal moment when the New Republic confronted key Imperial holdouts on a remote desert planet on the Outer Rim. Taking place in the aftermath of the Rebel victory in the Battle of Endor, players will experience the events that created the massive, battle-scarred landscape of Jakku.