This CD Player extension got replaced by the CD Entrypoint. You can read about Entrypoints in this thread:
Compared to the CD Player the CD Entrypoint has the following improvements:
- After first setup of the CD Entrypoint radio-stream in Roon, CD playback can be directly started by playing the stream. If there is a disk in the drive it will spin-up an play.
- Besides seeking to a specific track also seeking to next and previous track is possible.
- Streaming latency is reduced.
- Metadata is acquired from MusicBrainz instead of freedb, as the latter is no longer online.