Yes. GPT-3 teaches us that a sizable fraction of "serious" writing is just remixing previously written content. No underlying insight required. This is embarrassing to humans.
Note where this won't work: directions on how to do something real. If you used GPT-3 to generate auto repair manuals, you'd get plausible manuals, but they'd be wrong.
I think quite a philosophers and writers would acknowledge there's nothing new under the sun.
The way I'd see it, what even good writers do is usually a loose weaving together of things that have been already read along with some customization. It's only occasionally, (very roughly guestimating), every couple paragraphs, that this loose weaving needs to become tight and exact. That's my working hypothesis for why GPT-3 sounds senseless every paragraph or two.
Also "remixing" content is arguably how we learn. It's why we write essays and do problems at school and university. It isn't until graduate level that people start generating or synthesizing new knowledge rather than restating it.
Maybe we'll go back to reading local papers or listening to local bands when that's the only way to differentiate.
That does not mean that most speeches express entirely the same thoughts, much less than most famous persons all have the same speeches, all the way from Hitler.
The same ML model would not even approach passing the Turing Test. How can anyone claim it can "impersonate" a famous philosopher? This is just absolutely misleading clickbait.
And in any case, this was a test of mimicry, not of creation so your conclusion is a bit of a nonsequitur, regardless.
Then it's quite ironic that the philosophers are among the easiest ones to emulate by the computer.