I was in the same situation and with the advice from Apple support I kept both iTunes Match and Apple Music running concurrently. The reason was that I have a lot of music in my family library that is not able to be matched with the iCloud Music Library provided through iTunes - music recorded from radio broadcasts or from very obscure albums or CDs - which through iTunes Match have been uploaded to iCloud so it is available on all my devices.
I was told that Apple Music provides a different service - it allows me to listen and add to my library anything available via Apple Music. If I stopped my subscription to iTunes Match then those obscure tracks not commercially available through iTunes would no longer to be accessible on all my devices. I therefore decided to continue subscribing to both services.
So it depends on the makeup of your own music library - if it is mostly albums that are available via Apple Music or you are happy for any rarer tracks not to be available on all your devices and computers, then just use Apple Music. But backing up your iTunes library before subscribing or stopping a service is recommended,