Feels to opposite to me. GPT-1 would have exploded the word count to about 10x and made it sound way more breathlessly influencer coded. GPT-1 would have written something that was 180 degrees opposite of what the post is communicating.
Perhaps you need to read it again a little more carefully?
I think it was hyperbole, and that the GP does not literally believe this was written by GPT-1, which did not produce coherent sentences.