If you go to the website linked above, it actually give samples of original, watermarked and the file difference. .
Additionally, I think there is a Tidal playlist of 4 selections called UMG watermark:
“https://listen.tidal.com/playlist/a26b6652-6eb4-4519-bb7c-ca395da27e0e”
and a spotify one:
“https://open.spotify.com/user/ivionday/playlist/3ZbRKMGb8nqXqZziwtC5ZY”
(just remember to not copy the ")
I saw a compiled list of known CDs maybe on Steve Hoffman’s forums. The one that shocked me was The Stones in Mono. That is a whole lot of money in watermarking. The interesting thing is for that release the DSD is watermark free.