If high-quality music files are integrated into the iTunes Media/Music/ folder, and the user uploads content to iCloud by subscribing to iTunes Music, and those files are then downloaded to other devices of the user; do those files when they are on the other devices have the same bit depth and sample rate that they had prior to being uploaded into Apple Music? I.e., are they bit-by-bit the same files that were initially added to the iTunes folder?
When you subscribe to iTunes Match the individual files that you added to your iTunes library on your Mac are not uploaded to iCloud. Instead they are matched with the existing high quality music files made available by Apple.
These are then downloaded on any new device that you access your library from.