What an argument to make in court. It can be proved false in minutes by the plaintiffs.
Seeding is opt-out, not opt-in… but it is usually a default that has to actively manually overridden. Most users never touch those settings. The average pirate downloading a torrent is seeding whether they know it or not.
The protocol absolutely does not enforce seeding. A client can lie to the tracker, cap upload to 0k. BitTorrent has no mechanism to compel one to share. Leeching a file, downloading and sharing no forward packets is possible. While the "social contract" of seeding is entirely a norm enforced by private trackers and community shame. It is not the protocol itself.
No, because those cases were pirating-while-poor. This is pirating-while-trillion-dollar-corporation, which falls under a completely different section of the law.
It is interesting to follow how this plays out for Meta and how that will impact future cases.