I'm curious - surely there's still some single point that would let the rotor fly away? What does it mean that newer helicopters "doesn't have" this? I mean the rotor is attached? It's a single axel? There are scenarios where the rotor falls off?
There has been at least two cases recently of the main rotor blades as a whole detaching in flight. Gearbox failure caused the second crash [1]
On the older 'teetering head' designs like the Huey, you can bump the mast (rotor shaft) in aggressive nose overs or low g conditions which would also separate the rotors from the aircraft.
I imagine that's hard to do while in operation.
Meanwhile, a heli has autorotation, which is quite convenient in various failure modes.