Fallen have been our biggest enemies since the end of the Golden Age. We've had multiple wars throughout our history with them. I think its fitting for there to be another Fallen themed battle. I'm sure plenty of players would have loved playing a part in Six Fronts, even more so in Twilight Gap (the battle, not the map), so having another major one would be amazing. I can only assume that it has something to do with Twilight Gap and Six Fronts, since Saladin is the centerpiece of the leaked photo, ans Saladin is an Iron Lord.