Wise decision to keep iTunes Match regardless of the reasons. iTunes Match primary function is the storage and access of your
entire Music Library. Regardless of whether you cancel or remain a member of the new Apple Music service, your assured that
your music library is a safe. The reason you didn't see any noticeable upload to iTunes Match is that your music library was
already scanned and matched when you subscribed to the new Apple Music service. Even though this is primarily a music
streaming rental service, your music was matched. Not quite the same way as iTunes Match but identified nonetheless. Let's
say you choose not to continue Apple Music come Sept 30th, your device will then be more or less controlled by iTunes Match.
As for the DRM issues, this will probably be corrected with a software update as it relates to the manner in which that music is
treated should you cancel the service. They'll fix it but either way, that iTunes Match service will eliminate all that should you
yup unsubscribe to Apple Music. Hope this helps you out.