Well Valve is generally very positive about their modding community. EA on the other hand, the money hungry bitches they are, won't allow anything unless they can make a buck off it. None the less it might not hurt to try and ask all parties involved. If Epic, EA and Valve all give the okay to promote the game (on Steam for example) and as long as no profit is made, there should, theoretically, be no problem. However lawyers in three piece suits have been known to prove me wrong in the past so don't take my word for this .