If youtube-dl disagrees with the takedown, they need to take it up with the RIAA. If the RIAA - or a judge - decides in favor of youtube-dl, Github can restore the repository.
This is how things work; it may not be how you'd like things to work, but I doubt you've ever been involved in any part of a DMCA takedown request (as the sender, receiver, or the person that had their stuff taken down).
This is how things work; it may not be how you'd like things to work, but I doubt you've ever been involved in any part of a DMCA takedown request (as the sender, receiver, or the person that had their stuff taken down).