Sometimes when a package isn't migrating to testing but is outside the
migration window for the urgency used, so should have migrated to
testing, there isn't an RC bug yet because no-one has noticed the issue
yet, which means the autoremoval hasn't started happening yet. In those
situations it would be interesting to have how-can-i-help notify the
users that the migration has been blocked and needs reporting/fixing.
This would be especially useful during the freeze so that people are
reminded of the need to file unblock requests.