Nothing to see here. These performances are from 1984, which means that the recording companies that own their copyright have the right to block them in the US and other countries.
Well, if the uploader's using copyrighted recordings rather than a midi or performing the pieces themself or using a more liberally licensed recording, it is understandable. Bach's pieces may be free but musicians' performances of them aren't.
Doesn't youtube have an option to allow the copyright holders to monetize the videos in these cases? i.e. Get a cut of the AdSense revenue that would otherwise go to the uploader? Did this user choose not to split that revenue and instead opt to take down the videos, or did the record label force the takedown? It seems to me that it would be interest of the record label to take a cut of the profits off of recordings that would otherwise not make them a dime.
Get permission to play clips from a generalist record label like Naxos. Typically they're more than happy to oblige, for obvious reasons. People do this...