See that's the thing: I AM talking about Libertarians. Libertarians are just as arbitrary as anyone else with their speech definitions. They all gladly support a variety of political ideology and content, but some people's beliefs and posts conveniently won't meet these operators' standards for "political ideology" or "content".
Go ahead and tell me your subjective opinions about what counts as free speech. You say that pedo content should be blocked; do you consider pedo content to be speech?
I think Nostr is more than prepared for the attention of individual nations. I am skeptical about several parts of the Nostr protocol, but when it comes to the kind of legal threat you wonder about, it is clear to me that Nostr was designed with that as a central consideration. The answer is that people will migrate their servers to countries that are more free and the network will be unaffected.