m3u (or really anything that relies on file names to reference media assets) would be a potential disaster... all kinds of weird stuff makes it into your parser when you're dealing with a large enough catalog. I used to work in streaming media, including with some m3u-based legacy systems, and dealt with a pile of edge cases a mile high.

But thankfully, the industry solved this problem themselves: ISRC (International Standard Recording Code) is already used all over the royalty reporting side of the industry because it specifically solves the problem of referencing an individual recording of a work.

DDEX is a content delivery manifest format the industry also uses for this kind of purpose (sharing complex metadata about recordings in a standardized way), but its an 800lb gorilla of a format and not super consumer-friendly.

These are things that are all over the back offices of your favorite streaming service, but mostly transparent to the consumer.