I'm not quite sure how this would work. Are you saying is that the shielding on the copper wire has failed?I don't know about the strictly mechanical versus the electronic/electro-mechanical aspects.
I tend to think that microphony is an artifact and the real (primary?) driver is the fact that wax potting displaces the air between the windings with wax, a higher dielectric constant material, causing an increase in distributed capacitance. But, I can't discount the mechanical aspect out of hand.