Not all network interfaces get predictable names

[Joerg Rennefeld]

The raspbian stretch release enables "predictable network interface names".
However this does not work for all network interfaces.
I have three network interfaces on a RPi Model B.
(The internal interface, and two USB Ethernet adapters)
Only the internal interface (which is also a USB Ethernet Bridge internally) gets a predictable name in form of enx123456789012.
The two external USB Ethernet Adapters remain at eth1 and eth2.
This is with a fresh install of raspbian stretch image on sd card.

A probably related issue is that manually renaming the interfaces with a udev rule in a .link file does also not work.
The boot log shows error messages in form of:
raspberrypi systemd-udevd[143]: error changing net interface name 'eth2' to 'external-nic': Device or resource busy
systemd-udevd[143]: could not rename interface '4' from 'eth2' to 'external-nic': Device or resource busy