It’s not the same. OG iTunes Match replaces your music with non-DRM versions. Apple Music replaces all of your music with DRM versions that you’ll lose access to when you stop paying.
That’s why I still pay $25/year for iTunes Match.
This is incorrect. I say this from experience because I've tested this specifically. If you download a song from Apple Music it's DRMed. If you match an mp3/aac version of the same song then it matches with the version from the iTunes store (i.e. not DRMed). You can mix and match both within the same library. If you're paying for AM and iTunes Match you're wasting money.