Is it not possible for the gate to short circuit to the drain, delivering 12 V to the MCU that way? I would like the MCU to be protected in the event a MOSFET fails e.g. due to ESD damage.
I think the internal clamping diodes are only good for 1 mA which would be exceeded if the drain and gate are shorted: https://www.avrfreaks.net/forum/clamping-diodes-0