Seems implausible. For one obvious example, any web store that sends you MP3s you've purchased via e-mail (I've used a few) would now no longer function because GMail would delete the MP3s before you could even download them to listen to them.
Difficult to confirm or disprove without a few examples (artist name, track name) that people can test with their own legit (copyrighted) MP3s.
Difficult to confirm or disprove without a few examples (artist name, track name) that people can test with their own legit (copyrighted) MP3s.