If the America's Cup organization doesn't want anybody else using that name, let them sue Sea Cliff Yacht Club.
ISAF should stay out of it. Their self-assumed power has gone to their heads, some of which are in a very dark place.
It sounds to me like it is possible one of the two catamaran events approached the America's Cup authority to try and resolve the dispute (to get it sided to them). If that is true...talk about a backfire!