EA’s pre-order bonus is set after Episode VI.
The Star Wars Battlefront Battle of Jakku map is set one year after The Battle of Endor, featuring a fight to completely eradicate the remaining Imperial forces from the area. Expect plenty of exploding ships heading to the surface of Jakku as you destroy the empire or fight to keep it alive.
Battle of Jakku is a free download for pre-orders which is due on December 1st. It will be made available, for free, for everyone else a week later.