I mean, have you actually read the text at the link you provided? Or just remembered something, googled quickly and sent a random hit without reading it? The quotes under "What do lawyers say? Listen to what a several Intellectual Property Lawyers are saying on “Are book summaries legal?”:" certainly seem to be closer to what I was claiming.
> If you want to write a summary of any novel, without quoting from it, you are free to do it
> Copyright does not protect ideas, only a particular expression of those ideas
> You would likely get in trouble only if your summary contained long excerpts directly from the book
> As long as you do not quote directly from the book, or copy any of the content, then writing a unique summary is not illegal. You can mention the title, you can even quote sentences from the book as long as they are cited, you just can’t reproduce chunks of the content
etc
(I'm also not sure whether this article is just blogspam or itself AI generated)
> If you want to write a summary of any novel, without quoting from it, you are free to do it
> Copyright does not protect ideas, only a particular expression of those ideas
> You would likely get in trouble only if your summary contained long excerpts directly from the book
> As long as you do not quote directly from the book, or copy any of the content, then writing a unique summary is not illegal. You can mention the title, you can even quote sentences from the book as long as they are cited, you just can’t reproduce chunks of the content
etc
(I'm also not sure whether this article is just blogspam or itself AI generated)