To the extent that media outlets apply journalistic ethics or standards (which really only came about in the early 20th century), they have always done so voluntarily. The gov't has never placed such ethical rules on them. Because as a very liberal SCOTUS said, 1A prohibits it.
The liberal Justice Kagan also made clear last summer that even when technology and the media changes, 1A protections for them do not.
Over the past decade and more, whenever SCOTUS has prohibited gov't action under 1A, it has almost always been done with the liberals on board recognizing SCOTUS rights. It's been the MAGA Justices like Alito or Thomas (who wants to get rid of NYT v Sullivan) who have frequently been against it.