So the conspiracy theorist in me believes they may see this archiving as a threat for their current copyrights. So often modern copyrights holders get their copyrights invalidated when trying to enforce and litigate against others by someone finding an older work that predates the more more recent one. The Happy Birthday song got invalidated by an older work of "Good Morning to All" [1]. Having this database out there, it won't take long for someone to fingerprint this music that hasn't ever been stored in a digital form to use to invalidate claims using newer music. A certain cord progression or beat or a creative lyric and rhyme long forgotten in this old music could endanger parts of their current music catalog.
[1] https://www.nbcnews.com/business/business-news/u-s-judge-rul...