That's probably not the point the author is trying to make. In the book humans are trying to make sense of the artefacts lefts by the aliens, but are only able to do so slowly. The gap between human understanding and the aliens who built the artefacts are just to large.

The book never tells us that this is actual trash, it's just a theory. If the theory is true however, the aliens might also not understand the damage they've done, it's just a bit of littering to them. Or they don't care, they just destroyed an ant hill, so what.

The author of the article might have a bit more faith in the current generation of AI than I do, I don't believe that LLMs are really capable of creating that big a gap. The discoveries they make are all based on human knowledge and understanding, so we can comprehend the foundations on which they are built. Now if models can train and iterate on their own, to a much greater extend, then maybe, some day, in the far future their discoveries could leap frog humans to the same degree as the aliens in "A Roadside Picnic" and not understand that their output is damaging to us. That's just not going to happen with our current LLMs, they aren't going to scale up to that extend. There are already articles suggesting that we're almost at the peak of what they can do, with the resources we allocate.