We all know by now that Battlefront is staying relatively within the confines of the Original Trilogy. Even though the game will be expanding to planets like Bespin and even to the Death Star in the coming DLC, it seems to be that the limits of the canon will be stretched no further.
In a conference call, EA's Blake Jorgensen says "You can't make a game in Star Wars that violates the canon of Star Wars. Meaning, you can't take something from the future and bring it back into the past unless it's a reference.”
It would appear to be the nail in the coffin for any Force Awakens DLC hopefuls. However, he did say that they were trying to stay close to the movies, and that future Battlefronts could draw from the Sequel Trilogy.
“We're trying to stay tightly connected to the Star Wars beat for future movies, and we will obviously in future Star Wars games be able to tap the new characters and vehicles and so forth.”
The Battlefront team is presumably kept on a pretty tight leash with their Star Wars content; very few fandoms are as viciously protective as that of Star Wars, of which I consider myself to be a part. It's good to know that we'll be seeing new movie era in the future, despite any cynical misgivings that it was purposely kept away just so they could cash in on the sequels.
None of this explains Vader's presence on Jakku a few years after his death. But I digress.