Though I have never flown one, I think the Hiller 12E was something of an exception, in that the blades were conected to a fly bar with gyroscopic and aerodynamic properties. Perhaps there could have been a tolerance for a flight control to swashplate/fly bar control loss, but I very much doubt that a flybar to blade control loss would not result in immediate loss of control.
Though blades generally do have their feather axis pivot point forward of their center of lift, there are many other factors which would prevent a blade from seeking its own trailing pitch position based upon aerodynamic forces alone.