I think I follow what you're saying: people will be regulated offline, and that will affect what they are willing to say online. But obviously lots of people are using pseudonyms and it would usually not be worth the resources necessary to figure out who they are. But yes, anyone who is willing to put up a real name or business name that connects them to the real world can be held accountable in the real world, so real-world laws apply to what they say. This increases the credibility of what they say compared to someone only willing to use a pseudonym.
Discussion
I'm speaking more in the context of the lightning network, not necessarily Nostr.
Although, Nostr is pretty unstoppable, but relay businesses will be targets for regulations, but it will be pretty ineffective. Users, however, will moderate content through blocks and reports. Before following, they'll scroll through previous posts in order to complete their due diligence.