Just to clarify: iTunes Match makes all items in your iTunes collection available online for access to your other devices. Songs you have purchased will be available, as with 'Tunes in the Cloud'; songs you have for example ripped from CDs you have bought will be matched by the version in the Store if this is available; if it isn't available your copy will be uploaded for access by other devices.
There is a limit of 100,000 songs - this applies only to items not available in the Store (as purchased items are already available online). There is a charge of $24.99/£21.99 per year. The storage for these items does not count towards your iCloud storage space (indeed, though marketed as being part of iCloud it's actually nothing to do with it). Items in iTunes Match are not affected by DRM (Digital Rights Management which restricts where you can play them).
Once downloaded you can still play them if you terminate the subscription (though in that event you can't make further uploads or downloads).
As to Apple Music, as with iTunes Match, items which are in the Store but you have ripped from CDs, will be available as part of this, but if you don't also have an iTunes Match subscription DRM will be added to them and they will not be playable if you terminate the subscription.
Items you have ripped from CDs or obtained otherwise which are not in the Store's library will be uploaded in the same manner as iTunes Match and will not be affected by DRM.
So any matched items you re-download will be subject to DRM if you don't also have iTunes Match: do not delete your originals.
https://rfwilmut.net/notes/applemusic.html