What is the percentage of content hosted on youtube actually under control of the RIAA vs other content? If less than the majority of content on youtube is theirs, what gives them the right to have a tool removed for downloading content from a service that's not theirs and which they don't own the majority of the hosted content?
Why does the tool being hosted on an American website make any difference?
YouTube's content doesn't all belong to them, they don't even own the majority of the content on there and a huge number of users and creators on youtube do not live in or fall under American jurisdiction which means neither does the content they create, so again, why should the RIAA have the ability to do this?
I am guessing they'll find a country with more respect for freedom than the USA and host it there. All the devs will obviously have the full repo and history to put it elsewhere.
If they hosted it somewhere else, there would be different laws restricting how people all over the world use it.