It is not really a matter for an extradition judge to rule on whether what Assange did falls under press freedom. The US courts would have to decide that. If however the case had been identical but coming from China, the judge would still not have ruled on press freedom, but would have likely considered that the Chinese constitution and court precedents do not offer sufficient guarantees that there would actually be a fair trial, unlike in the US system.
Whether you agree with this point or not is another matter, but I don't see the ruling as being either for or against press freedom, by my understanding.