If I'm correct, some elements of the current Falcon, like the doors and wagon rear will be over ten years old by the time the orion goes on sale.
Almost. The turret (from the A-pillar to the C-pillar) will be 9.5 years old when the Orion is released. The only change to the turrent in the time was starightening the top of the windscreen and rear windows (sedan) only when BA was released in 2002. Once Orion is released this last link with the unloved AU model will be gone.