NNNNNNNNOOOOOOOOOOOOOOOOOOOOOOOOO
This is pretty clearly a case of Google threatening to sue, and while it’s unfortunate it’s pretty inevitable for something like this. Very sad :(
I assume GitHub links will also be purged soon, grab everything while you can if you’re interested…
At the very least the current Vanced app should work for a while, YouTube is unlikely to need an update to work.
A list of alternatives: https://gist.github.com/SkyyySi/1b621c7c20ae7e0865a8ac428156c1cf (not mine, found it on reddit.)