I think many here are missing the point being made. Of course there are stylistic differences between some groups of artists. The thing is that they probably aren't coded by skin color let alone period location etc, so of course it will bleed. Playing some swing and expecting it to continue to stay within very blurry racial lines is unrealistic, silly, and maybe irresponsible for a recommendation algorithm.

As it's been said, there are better methods of discovery for this purpose. In your example, I'm sure there are Spotify playlists for Italian disco that have been curated.