Not necessarily. If this situation goes viral and leads to an overall increase in piracy, someone at RIAA will have to answer for it.
Copyright cartels live by bullying. It is not important how much of the takedowns are actually effective, as long as they get to dominate the news with their lawsuits. Because only that will already deter al lot of people. Just drag everything on forever and have an occasional success that you can trump on every news channel. That is enough to spread fear. And that works also in other countries, like The Netherlands, because they will have some representative organization there (Brein, in this case) that is happy to take on the role of the bully for a small amount of cash.
Thing about software is it doesn't need a lot of people. Just a handful.
oink.cd was viral.
PopcornTime is viral.
The Pirate Bay was/is viral.
RIAA doesn't care. Their main business is extortion racket. And it's extremely lucrative.
And it's extortion on all sides. They extort money from DMCA and copyright lawsuits. They extort money from artists. They extort money from music services.
The RIAA and other copyright holder representatives have automated submitting a DMCA takedown request process ages ago, and now submit thousands a day to e.g. youtube. Youtube in turn has automated taking down content that receives said requests and probably a big part of the appeal process as well. Is Github that far already?
Microsoft bought Github for 7.5 billion dollars. Github is a website wrapping a git-server; you know Microsoft could have built their own for a lot less money. The didn't buy the technology, they bought a network, its data and a brand. They are trying to improve their reputation with the open source community. It's really hard to measure such a thing, but this RIAA take down reduced developer trust. If Microsoft chose to fight a legal battle, win or lose they would win on their branding front. They would signal that they are defending open source.