In Apple Music today they indicate if the track is lossless and if it's taken from a master. I believe that lossless studio master rips are 24-bit / 192 kHz (CD is 16-bit / 44 kHz).
The originals are whatever the artist has. There isn't going to be a standard, especially for indie music, and there's nothing magical about 24-bit/192khz that makes it a good format.
CD quality is already perfect, impossible for a human to hear any improvement on. Except of course that it's only available in stereo post-mix.
