“Recently, I uploaded a production of Gilbert and Sullivan’s Trial by Jury to YouTube, and it instantly got hit by four copyright claims.”
Gilbert died in 1911 and Sullivan in 1900. The recording was brand new. The claimants still get the ad money during a 30-day appeal, and the appeal goes to the claimants themselves. Content ID was sold as protection for rights holders. In practice it is a toll booth for anyone willing to file a claim.