I think that the FAA's perception of propeller blade shedding can be inferred from the design requirement:
Sec. 25.771
Pilot compartment.
............
(b) The primary controls listed in Sec. 25.779(a), excluding cables and control rods, must be located with respect to the propellers so that no member of the minimum flight crew (established under Sec. 25.1523), or part of the controls, lies in the region between the plane of rotation of any inboard propeller and the surface generated by a line passing through the center of the propeller hub making an angle of five degrees forward or aft of the plane of rotation of the propeller. .............
This is a design requirement for the pilots, but not the passengers.
Ice seems to come off a propeller in line with the disc. I have broken a propeller ice panel on the baggage door of a light twin with the prop shedding large chunks of ice in flight. The contact point was directly in the prop disc. A blade developing thrust would seem to have a range of 5 degrees if the FAA design requirement is an indicator of experience. It's worth noting that the instant that a blade might release from the hub, it stops developing thrust, so would be acted upon by centrifugal force primarily. That said, when the propeller damage is a result of a ground strike, I imaging the physics change.