Nope. If he isn't signed no one has a way to pay or knows who to pay. For example, SoundExchange has lots of dollars waiting for artists they can't find, at least so I am told.
So the next question is what if I play unsigned artists what happens to the report? The artist and song are reported as usual. Sometimes unsigned artists cover copyrighted songs so it is best to report anyway. Once the authorities get an unsigned artist or song the if they don't have match in their system it is in essence tossed out.
Marvin
Marvin