Wow, more time spent on this than I care to admit, but, it turns out you can't use eth* names on Linux anymore if you actually care about automation! TIL.
Default device names for anything #mgmtconfig manages are now going to be meth0, meth1, methN, unless someone has a better idea.
https://github.com/systemd/systemd/issues/16665#issuecomment-669167184
