He later post this on his official message board (why does he have an official message board?) to TMNT fans:
Fans need to take a breath, and chill. They have not read the script. Our team is working closely with one of the original creators of Ninja Turtles to help expand and give a more complex back story. Relax, we are including everything that made you become fans in the first place. We are just building a richer world.No Michael, I won't chill. Did no one else here see what he did to the Transformers? The last thing I need in the new TMNT movie is huge explosions that make no sense in a ninja movie; shaky, vomit inducing camera work and Shia Labeouf. But Aliens? I'm all for expanding the back story of the turtles. I'm also aware there is precedence in the TMNT universe for aliens, but the turtles themselves are turtles, from earth. I don't care if the Ooze comes from Uranus, the turtles are mutants from earth.
Big thanks to Ninja Pizza for all their up to date TMNT news including this topic. Great blog, go check it out.