rsvman2 I'm not sure I've ever heard him make that claim. If you have a link for it, I'd be interested. I think his claim is that he can teach you a way to swing that is different and will add to your swing speed. Just loosening up the wrists added (or appears at this moment to have added) swing speed and yards for me. If he can lift an 89 MPH swing to 95 with less effort, I think most players would take it.
BTW, the message behind my post wasn't about Wilson, per se, but that I achieved his end of a "soft wrist" by just changing my grip so that it was more difficult to manipulate the club with my hands. The grip I described literally creates a hinge in line with what Wilson teaches.