This could be due to them receiving D-Notices.
Now, along comes a situation which looks a lot like an attempt at journalistic suppression by the state. The incentive for the media to go along with any potential D-notice has evaporated because this is just censorship by other means, and if you're going to censor us anyway, why bother with D-notices? Issuing a D-notice over harrassing a journalist (via their family, in this case) would be something of a bodyliner, and I don't think even the British press would have a hard time figuring out what to do about it.
If anyone issued a super-injunction over this, the British media would see it as a challenge as to who could ensure the details were insinuated in such as way as to ensure the widest distribution.