While some audio alert that the controls are being pulled in opposite directions is something to consider, it's already noticeable by the PF that the PM is no longer PMing and it is very obvious to the PM that they are also no longer PMing. Unless one or both told the other about this as a desired change, I think that a little voice isn't going to clarify much about conflicting inputs; perhaps it should say "REDUNDANT INPUTS: WHO IS IN CHARGE OF FLYING THIS PLANE?"