I've wondered since the BRZ was officailly announced as a RWD coupe if some WRX development, engine, suspension parts, chassis, interiors, body designs, ect. could have been going on in conjunction with the BRZ, but so much attention was given to the BRZ that no one noticed. Of course, I am old and my mind wanders/wonders all the time.
Think about it. Since Toyota apparently put up most the development money, why not use it to develop parts that could be used in other models? Subaru has already said that without the BRZ a new WRX/STI couldn't happen. Maybe Subaru meant they now had more of their own R&D money available for WRX/STI development..