The original one is still there. Systemd knows even about that, it's differentiated as MAC vs PermanentMAC.

There are, unfortunately, some older devices (like some Sun systems) which use the same MAC address for every network interface on the device.

i thought about that, but couldn't you access the hardcoded address to identify the card?

but you also want to be able to change a card in a server without the device name changing. at least that used to be an issue in the past.