The entire game is one big retcon.
I mean, what about the Rebel Alliance? They completely remodelled it and introduced Starkiller and Kota on it. At least they didn't removed Garm, Mon and Bail from it (although I'm not quite sure Leia was with them originally).
Again with the Alliance: the eagle esque symbol was, as shown on the game, "stolen" by Leia from Galen's house apparently.