Eugen Rochko on Nostr: One more thing. I am not a lawyer, but in my understanding the "default" license for ...

One more thing. I am not a lawyer, but in my understanding the "default" license for any works you publish on the web is not "public domain", it is "no license". Content published on the fediverse cannot be used for anything, legally, except the intended function of the service. It is only if you want to to give more rights that you'd need "content licensing support". In that sense I also don't see this as a show stopper for federation today.