Actually, she claimed that she can't be held liable because the alleged victims were public figures, and that the required standard of proof for defamation charges where the alleged victim is a public figure were not met.
> The appeals court decided that she does indeed qualify as a journalist in this case.
No, it, explicitly did not. It said that the test for libel against public figures articulated by the Supreme Court does not rest on a determination of whether the person accused of the defamation is a journalist or not, it depends on whether the subject of the claim is a public figure and the matter under discussion is one of public interest.
It's not about Cox getting some special journalistic privilege, its about the Ninth Circuit rejecting -- as every other circuit that has heard similar cases has rejected -- the idea that the Supreme Court rule on defamation of public figures is a special journalistic privilege at all.
The whole "journalist" misrepresentation is the institutional media pretending that the courts are simply (and implicitly unacceptably) adjusting the scope of a special privilege that belongs to the institutional media, rather than rejecting, again, the idea that the First Amendment creates special privileges that belong to the institutional media.