>But you never checked the accuracy of your information before so
They didn't say that and that's not a fair or warranted extrapolation.
They're talking about a heuristic that we all use, as a shorthand proxy that doesn't replace but can help steer the initial navigation in the selection of reliable sources, which can be complemented with fact checking (see the steelmanning I did there?). I don't think someone using that heuristic can be interpreted as tantamount to completely ignoring facts, which is a ridiculous extrapolation.
I also think is misrepresents the lay of the land, which is that in the universe of nonfiction writing, I don't think that there's a fire hose of facts and falsehoods indistinguishable in tone. I think there's in fact a reasonably high correlation between the discernible tone of impersonal professional and credible information, which, again (since this seems to be a difficult sticking point) doesn't mean that the tone substitutes for the facts which still need to be verified.
The idea that information and misinformation are tonally indistinguishable is, in my experience, only something believed by post-truth "do you own research" people who think there are equally valid facts in all directions.
There's not, for instance, a Science Daily of equally sciency sounding misinformation. There's not a second different IPCC that publishes a report with thousands of citations which are all wrong, etc. Misinformation is out there but it's not symmetrical, and understanding that it's not symmetrical is an important aspect of information literacy.
This is important because it goes to their point, which is that something has changed, in the advent of LLMS. That symmetry may be coming, and it's precisely the fact that it wasn't there before that is pivotal.