It is a huge part of iCloud. Why do you think there are cloud icons all over iTunes? Match uploads all your music to the cloud or matches it to music on the cloud already. Then it lets you download music from the cloud to any device and syncs all your iCloud iTunes music to all synced devices.
I understand what iTunes Match is. I'm a subscriber. And no, it does not sync your music to your device. You have to manually initiate the download for any particular track or album. I have over 125 GBs of music. How is iTunes Match going to sync that much content on my 16GB iPad 2? The answer is it can't, and so the user downloads content manually from the cloud. This is not automatic syncing.
And just to clarify, i'm speaking strictly from their marketing perspective of the service that is called "iCloud", and it is a fact that iTunes Match does not use your iCloud storage, is not in the iCloud preferences for both Mac and iOS, and as I said before, does not automatically keep your devices musical content in sync with one another.