See discussion at https://community.metabrainz.org/t/style-2443-what-to-do-about-bandcamp-links-that-contain-no-streamable-or-downloadable-content/674689. These links contain information about tracks tied to specific albums, but the tracks themselves cannot be purchased or streamed from those links, so existing URL relationships do not work.

Tracker for releases that need this relationship: https://musicbrainz.org/tag/information%20page