I would to like suggest checking the following direction:
1. principal question: can we update the netdev device address after it is already set during probe? I meant perform another:
memcpy(netdev->dev_addr, hw->mac.addr, netdev->addr_len) up to demand
2. We need to work with Intel's firmware engineer/group and define the message/event: MAC addressis changed and should be updated.
As I know MNG FW updates shadow registers. Since shadow registers are different from RAL/RAH registers - it could be a notification that the MAC address changed. Let's check it.