Recently listened is an automatic list like a log, not user curated. I would never expect to be able to delete things from that list.

I don't need an audit log for my audio. What I do need however is to remove something so it doesn't influence the algorithm. I may not remember every time I play music for a kid to turn on the right mode.

That would also then require them to invalidate caches and rerun scripts to rebuild those lists and recommendations, which costs extra compute.

Invalidate the recommendation cache

You mean like, when a new song is added to the list???