I don’t remember whether Linus said blocking ads is a crime. It isn’t a crime, and that’s really important.
At that point piracy becomes a meaningless phrase when even the FBI endorses the piracy tool.
I don’t think it’s right to call something a piracy tool. We have the similar discussions about “hacking tools”. Nmap can be used for commuting crimes, just like BitTorrent, the Internet or my kitchen knifes.
With this it isn’t a problem for the FBI to promote “piracy tools”, since almost everything can be used for good and legal purposes. uBlock is one of the most important tools to be secure on the internet, just like nmap to make sure systems are secure.
He can argue it’s morally unfair for people to legally visit YouTube and legally not disable Adblock to view his channel, but it’s not a crime.