After enabling iCloud Music Library, what is on the phone is controlled from the phone, iTunes no longer controls that. All music files on the phone when switching on iCML should remain on the phone. Any music added on the phone via 'Make available offline' should also stay on the phone. Any music in the 'My Music' section in iTunes should be available for streaming and download on the phone. I am not aware of any way to achieve the automatic download of the set of music the autofill put on the phone (highly rated songs, frequently played songs, new songs) with iCML. I guess the ability to download or stream any music directly from the device is meant to make that function much less necessary (ie, you can still get at all music that autofill would have put on the phone simply via streaming).
