iTunes Match & Apple Music
Should one ever cancel the Apple Music service, it means
any downloaded songs from the service can't be played.
That's logical if you cancel as all benefits cease to exist.
If you plan to have Apple Music at $9.99/month indefinitely,
then you might choose to cancel iTunes Match. If not, I
advise keeping iTunes Match assuming they fix the artists
and Album organization that went haywire last week.
iPhone 5s, iOS 8