This is very important.
Maybe it's by design but it's then a wrong design because people can't subscribe to all and every possible authors/composers on earth — they can't even guess who could work for/with a subscribed artist (performer).

Example : http://musicbrainz.org/edit/16629893 and http://musicbrainz.org/edit/16629869 should appear in http://musicbrainz.org/artist/5c5cb762-d95e-47af-a7bf-35171eeab8e6/edits for proper review.