That isn't infringement. Any more than transformative work is.

An "abstract copy" of a text is perfectly legal, e.g. Wikipedia Plot synopsis. Even verbatim copies can be legal.

Google had a lawsuit about this when they were doing their book scanning project and they won. It's fair use. And that was copying, word for word, GPT just gather some vague ideas of the work, it doesn't store or has access to actual copies.