No, it has negative feedback. Hysteresis requires positive feedback.
I look at the pickup coil as a transducer which converts EMF to a current. That current is multiplied by the impedance of the feedback loop, giving a voltage out. I have no idea how you would get an audio signal for EMF frequencies above the audio range. Perhaps it is designed to pick up mains fundamental and harmonics,
lightning(?), and maybe ghosts. Anyone know the frequency range preferred by ghosts?