This is an apparent separate bug discovered in the course of bug 67805.
Niklas suggested, "LC issue is possibly caused by incorrect fallback merging, because L10nupdate contains update for ru, but not for uk (because the translation is already up to date for uk):"
Version: wmf-deployment
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=67805
https://bugzilla.wikimedia.org/show_bug.cgi?id=70686