On the surface I understand what you are saying, however I think you’ll find that anyone doing what your talking about is someone who would never license music to begin with.
Almost all buyers are looking for high quality audio they can manipulate, cut up and sync to their track perfectly to create a professional final product. You can upload lower quality MP3 files to AdRev that will do the trick to cover identification.
Without editing capabilities, high resolution files and a legal document to back up the use of audio, audio swap is hardly the equivalent of licensing music. I don’t think the majority of people, even being aware of it, would feel comfortable using it or find it sufficient for their project needs.
This was also considered before AdRev was made available to authors.