Hobie Cat Co. doesn't control the class rules for the 17. ISAF does - it's an International Class. The process for change is laborious and takes a long time, especially for a significant change like the construction / design of a new sail.

It would only happen if a large majority of the Hobie 17 racers wanted it to happen. I don't think most of them are ready to run out and buy another $1000 sail, even if it gave marginally better performance and lasted longer.