"opening up applications to would-be astronauts with a physical disability"
In space, I really don't see how that can be a problem. Legs are actually a hindrance, if I'm not mistaken, since you mostly need your hands to get places.
The main use of legs is for physical training to try to counteract the effects of freefall. I wonder how the ESA is going to manage integrating that part into a parastronauts' physical training.