> it wasn't published, and the advance was retracted.
Not because they didn't think the writing was high quality. The quality of the writing is what led to the bidding war. The advance was retracted because the publisher can't get exclusivity if copyright protections don't hold due to the novel being AI generated.
Bidding wars are caused by all kinds of things, and quality is only one of them. It's the only one that gets said in marketing material though.