It seems that if an artist no longer is on Spotify, the artist URL (open.spotify.com/artist/XXXXXX) doesn't dissapear or become invalid, it still opens the artist page but it has no music. If you proceed to search for the artist in Spotify however, there are no results.
Can these types of links be reported/deleted? It can be a bit problematic/misleading that there are cached links like these in search engines like Google that suggest that the artists music is available on Spotify when it's not (links that you cannot get deleted from search engines as long as the link appears to be active).
Been wondering about this for along time...