They key phrase here is "prior restraint." That's not the issue here; the information has been published already. So the holding in the Pentagon Papers case (aka _New York Times_) doesn't apply to this set of circumstances.
Moreover, the Pentagon Papers case made no law. The opinion itself only reversed an appellate court decision and affirmed the judgment of a district court.
Read it yourself: https://supreme.justia.com/cases/federal/us/403/713/#tab-opi...
First Amendment law respecting the dissemination of classified information -- by "journalists" (whatever they may be), or otherwise -- is not as settled as people think, and it's my personal view that unless the Supreme Court concludes otherwise, Mr. Assange could find himself in very hot water, as Chelsea Manning did.
