I use composite genres to map albums to multiple genre-based playlists. E.g. a genre of “| Post-Punk | Goth Rock |” puts an album on my Post-Punk playlist and my Goth Rock playlist.
So I can experience the joy of using Siri to Longplay a random post-punk album, could you please add a playlist option to your Siri action?
For that matter, it might be fun to be able to target any tag. E.g. “Hey Siri, Longplay me an album from 1987”.