I'm more interested in the claim that this is the first book by an AI. To my knowledge, plenty of machine learning models have been used to produce all sorts of

I'm more interested in the claim that this is the first book by an AI. To my knowledge, plenty of machine learning models have been used to produce all sorts of texts. Is this really the first time a length of a book has been produced? Or is it a claim that this time it is an actual AI?