The northeast has lost some regatta's also,but they weren't really Hobie fleets anymore. Mostly open. My guess is that is the same elsewhere.
Actually, regattas in Div 9 have been mostly Hobies. After the decission by HCA, each organizer was given freedom to make their event Hobie only. No one decided this was in the best interest of their event, sponsors, or the sport.
I am glad to hear about the increase in H16s. Any increase in cat fleets is good for us all.