For display and bookkeeping on evergreen.jenkins.io, it is beneficial for the client to say that it's on the latest update level, even if that latest update level has no updates for this specific flavor.

I'm guessing that the client is not saving and reporting it's own update level if there are no specific updates to apply, I'm not sure of this though.

If the client has nothing to do for a given update level, it should say to the backend that it is up to date with that given update level regardless.