I must admit that I haven't had time to watch the video, but....

Maybe they haven't thought this through. I imagine the watermark will be very high frequency, so as not to interfere with the audible track - it should be easy enough to filter this out and re-digitise. For other forms of watermark, I'm guessing that recording to a (lossy) low bitrate MP3 would do the job nicely. Others will surely find more ways.

Edit-
What ever the watermark, how long will it be before you can download an ai program to strip it out? Also, if a watermark screams out ai, then a piece without a watermark suddenly becomes legitimised, confirmed as real performers, and copyright-capable.

Last edited by ROG; 1 hour ago.