Comment # 3 on bug 1169476 from pgnd _

The 'doesn't work with bridges' is a mising feature, not a bug?

It renders the system -- using a 'feature' that's documented as avaiable in the
release's officially supported version of systemd -- broken, and firing errors.

I'll disagree that's not a bug.

Option to backport exists, though apparently not trivial as you say.

Option to bump systemd version -- for this and many other reasons -- exists as
well.

Iiuc, 15.2 is locked at the same systemd version as 15.1 -- so we can expect
it'll be missing this "feature" as well, for its entire life cycle?