I have a vague fear that it's going to try and do something like Brave's "BAT" but for music that you have locally -- which I guess could work if you distribute your music for free (as I do for much of mine), but doesn't make sense if you purchase your music. I certainly can't see myself wanting to pay for the same music twice -- once for the physical or digital copy, and then again for "Winamp Attention Tokens".
Much more likely though that it's just another music streaming service.