Yes, that's exactly how it works:
How iTunes Match works.
iTunes determines which songs in your collection are available in the iTunes Store. Any music with a match is automatically added to iCloud for you to listen to anytime, on any device. Since there are more than 26 million songs in the iTunes Store, chances are your music is already in iCloud.3 And for the few songs that arent, iTunes uploads what it cant match (which is much faster than uploading your entire music library).
(emphasis mine)
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www.apple.com/si/itunes/ ··· s-match/