> Is revealing sources really a violation of "freedom of press"?

Well, when a confidential source has their identity revealed it's likely to go pretty badly for them. eg: many corporate and gov whistleblowers being fired + pursued extra-legally, Chelsea Manning thrown in prison, and so on.

So, (most) media organisations seem to resist doing the revealing.

Whether or not that falls strictly under the "freedom of the press" term or not though, is not all that relevant.

The concept of "don't reveal sources" is pretty basic, regardless of the term people use to describe it. ;)

So no hope of Harvard notation from the Beeb, then?

It's the ability to publish criticism and facts about the government without facing harm from doing so.

Revealing sources violates the trust those sources depend on to ensure the truth gets reported, and risks harm to those sources.