But I definitely remember hearing that message in the media for the last 20 years, and I don't recall anyone calling it "trolling" until it was directed at journalists.
I've wasted the entire morning looking for sources of this by now. Like you, I sort of remembered hearing that message over the years. But now that I'm looking, I'm not actually finding many examples where news outlets are seriously suggesting this.
Have you ever thought you knew something, but end up misremembering it? There are lots of people who swear they remember a movie called Shazzam staring Sinbad as a genie, but there is no such movie. There was a movie called Kazaam staring Shaquille O'Neal, and Sinbad once dressed up in similar garb when hosting a movie showing. But people conflated the two things.
I think that's whats going on. And if so, we should not be harassing journalists who had nothing to do with this.