Currently it is possible to submit a listen with empty artist_name and track_name but with artist_mbids and recording_mbid.
This results in showing listens with no information other than listen time. See attached screenshot.

That metadata should be fetched and used.
Not sure if this should be done in the back-end or the front-end.

If on the back-end, is it something we want to do at listen insertion time?

As a fallback, at the very least, the MBIDS should be shown on the listen aas a link to the MusicBrainz page.