To be fair, GPT is not a person. It's like a fuzzy database with lossy-compression. If they over-trained GPT on specific books, it could cite the books verbatim, which would then violate copyright and IP laws. (Not that I'm a fan of IP laws).

While I appreciate thinking of this in absurdity, you're being disingenuous here. It's like reading a book for a person with eidetic memory then asking for "writing in the style of so and so." And so you use exactly the sentence structure, the verbiage and even the paragraph style. When inspected, you perfectly reproduced the writing style, but effectively only changed a couple words to match the request.

You reproduced 95% of an essay, and 5% of it is yours. You didn't improve on the work, you simply changed the least amount of it you could to suit your purpose.

The way these systems retain the relative symbols is irrelevant if the structure and form of the original is what gives it it's value. The parameters are simply those things that are elements of someone elses copyrighted material. The lawsuit alleges that the books were used, well it's not too hard to get GPT to spit out gutenberg books, or to lie to it and get it to think other books it knows are now public domain and have it do the same. Paragraph and page you can get it to barf them back out verbatim.