Apple Music without iTunes Match

No. iCloud Music Library only scans and matches tracks in your library on your computer to tracks in the store, or uploads, those not matched, to iCloud, to make them available to other devices using the same Apple ID over iCloud.

It does not affect your library on your computer. If it was on, which is odd and you turned it off, them it just removes all the matched and uploaded tracks from iCloud.

Apple owns nothing, and your existing library would not be drm protected if it wasn’t originally.

iTunes Match and Apple Music are 2 separate services that are not connected to each other in any way. There’s nothing to disable from Apple Music to not use iTunes Match since they are different things.

If you mean the iCloud Music Library Option in Apple Music that is similar in function to iTunes Match, then the only thing you need to do, is to never turn it on.

iCloud Music Library is off by default.

See here: Turn on iCloud Music Library with Apple Music - Apple Support