I didn't even notice him in TDKR. Saw it yesterday morning so it's still fresh in my mind. He must have had his hair grow out or something, and I wasn't looking for him.
I'd imagine he was talking about TDKR intead of Ender's Game. He likely had a lot of screen time in Ender's Game, and must have been disappointed that he was treated like "just another child actor" on Nolan's set. Though I'm not sure why he's acting surprised.