I've seen that lots of people are confused regarding the matching and cloud functionality of Apple Music vs the regular iTunes Match service. Here's a simple explanation to define the differences between those services.
There are several ways to get music from Apple.
1.- Directly buying from the iTunes Store.
2.- Matching songs you already own, deleting them, and downloading fresh AAC copies from the store.
3.- Subscribing to Apple Music.
In all 3 cases, you receive the exact same AAC 256 file.
Now, in order to understand why Apple Music does not replace iTunes Match 100%, you need to understand this.
1.- If you buy songs from the store, those are yours forever, plus they will forever be in the cloud. You can download them multiple times, delete them, modify them, etc. The stuff everyone already knows.
2.- With iTunes Match, you are paying Apple $25 for them to rent you a space in the cloud for a year, AND (as the name says and most people forget about) you are paying Apple to match your songs to what they already have on the iTunes Store and only upload what's not in there, by doing that, you can delete your original copies and actually download a fresh high-quality copy from the store itself.
Here's the most important part... Some people do not care about this functionality, they only care about renting a space in the cloud. But some other people use this to upgrade their whole library and delete their original low-quality copies, and the cloud stuff as an added bonus.
Of course, to receive a fresh copy from the store, you need to own a copy of the song somehow (either legally or illegally, that's another story) but you need to somehow own a copy of the song to match it, that's the most important thing about Match (duh).
However, if you do not renew your subscription, your matched and locally downloaded songs will remain with you forever, free of DRM, of course, you will lose the cloud functionality, that's the big advantage of actually buying the songs, but the actual downloaded copies will remain in your library forever.
3.- Apple Music does offer cloud functionality, matches your songs and uploads the rest, but... It doesn't give you DRM-free files, it gives you .m4p files, so your matched music won't remain with you forever, and even if you keep paying for Apple Music they are only protected AAC files, not regular AAC files, plus, iTunes Match matches songs from the iTunes Store, Apple Music matches from the Apple Music catalog only, so if you upload some songs of The Beatles, they won't get matched, they will get uploaded, as The Beatles are not in Apple Music's catalog, but they are in the regular iTunes Store.
So, if you are still reading this, the point is... If you just care for iTunes Match solely for the cloud capabilities, you can ditch it right now, as long as you pay for Apple Music your music will be in the cloud. However, if you actually want to keep your files forever, and upgrade the files you already own (either legally or illegally, again, that's another story) you should keep iTunes Match as it complements Apple Music.
Plus, if you try to add a song from Apple Music to Your Music... If you bought the song from the iTunes Store OR if you matched it with iTunes Match, Apple Music won't allow it, it will recognize that you already own that song, that it is already in your library, so if you decide to download it for off-line listening, it won't give you an AAC protected file, it will give you a regular DRM-free file. That's the big difference between Apple Music cloud service and iTunes Match, but the cloud is the same, it just got renamed, iTunes Match is an extra, optional feature, they are not separate clouds, only one. Hence the "iTunes Match complements Apple Music" sentence.
Last thing... If you have Apple Music + Match, and you add an album or a track from Apple Music to Your Music, let's say... "Uptown Funk" and later on you decide to buy the song elsewhere, or somehow you got a copy of the song, and you upload it, it won't allow you to do it. It will detect that you already have the song and won't match it... So you are stuck with the DRM-file...
To avoid this, you need to delete the song from your music, (also deleting the offline copy if you downloaded it) and then add the copy you've got, and THEN upload it to the cloud, that way it will recognize it as a song you don't have in your music and finally it will let you download a DRM-free copy.
That way, when you go to the album or track in Apple Music, it won't let add it to Your Music, there won't even be an option to do so, as it recognizes that you already own the song... So to have a DRM-free copy you must delete the Apple Music copy first, it is not automatically done... It's a complete mess.
