We currently get youtube-dl from the WebUpd8 repo, which has two problems
Since YouTube occasionally breaks youtube-dl, and releases are so fast that bug fixes don't seem to get reliably backported by Debian or Ubuntu, maybe this is a package that should be rolling like Abrowser. I can't find an up-to-date PPA, but we can use Ubuntu testing. However, the version in Eoan wants debhelper 12, so maybe this won't work.
This merge request is for Flidas because Flidas users are currently affected but Etiona has the same problem, because the version of youtube-dl in Bionic is also broken.