I don't think there's anything new about it. The concept and legal framework for D-Notice (essentially: "soft" media gag order)[0] is more than 100 years old.
Specific, targeted actions like this are a far cry from dragnet responses like the snooper's charter or calls for banning encryption (at least any kind that can't be decrypted by the government). The danger of dragnets is that they pick up incidental thought-crime. It's why warrants exist.
Although certainly a case could be made that the media is in a better position than the government to decide what should be made public.