By that logic, The Joker, Gordon, Alfred, even Batman himself shouldn't be in the movie. Just because the other movies already had him doesn't mean this new film can't have a different take on it and make it fresh. I mean, you have to admit, Two-Face's turn in TDK was kind of weak.
His turn from Harvey to Two-Face was extremely strong. Everyone of course wanted him to last longer as a villain, but his
turn?? Absolutely amazing. Eckhart nailed it.
What I mean is, certain stories don't need to be told over again. Especially so soon after these Nolan movies. It's only been 5 years since Dent became Two-Face on the big screen in a billion dollar movie. Harvey Dent's legacy was also a big part of last years Batman movie. We don't need to see his origin for a couple of decades. You can still have Two-Face in this new series but he should be Two-Face already, and it shouldn't be so soon, not the next movie.
It's like Joker. We don't need to see a third Bat film where Batman is meeting the Joker for the first time. You cant do that any better. So you look for new ways. Use Harley Quinn as his "sidekick". A Young Joker who is only a few years older than what Ledger was when filming but definitely way younger than Nicholsons. Perma-white, short hair but a Joker that is his own thing in terms of personality. Have him in Arkham already. He's already met Batman off screen. So the first time the audience sees these new actors together in the same room, theres a familiarity between them already.
For the next few films (or more) they need to stay away from Ras, Talia, Bane, the League of Assassins.
You get my point? They need to bring new stories, new twists, new characters into this reboot. It's called a reinvention for a reason. Just like how Nolan's movies were a 180 from the Shumacher's. There were no sidekicks, no campy humor over-done, more grounded, different rogues. Even Bane and Two-Face were done in a opposite way in terms of story and characterization. In
Forever the focus was mainly on Two-Face the villain and he was more campy. In
TDK the focus was on Harvey Dent the good man, and when he turned it was darker and serious. They've exhausted the possibilities for the time being. We need a huge break from Two-Face (nothing more than a cameo) and when the times comes to bring him back full swing? He can Two-Face already in his 40s, dark hair, in a completely different story and world.