Can you tell me why NamePolicy=keep doesn't do the trick?

Looking myself for options to keep a Debian bare metal server I admin from going deaf and mute the next time I upgrade it... It still uses an /etc/network/interfaces file that configures a bridge for VMs to use, and the bridge_ports parameter requires an interface name which, when I upgraded to Bookworm, changed.

At this rate maybe I'll write a script that runs on boot and fixes up that file with whatever interface it finds, then restarts the network.