I think there are two different "neutral" concepts in play here now. Neutral can mean no TR blade pitch, which should be roughly the same as a TR drive failure, but neutral can also mean "provide enough torque to counter the torque from the main rotor".
I would think that if left to "adjust itself", the first kind of neutral would be most likely, while the second kind of neutral would be what one would want as a safety fallback for control failure.