It's possible there would be a market for this in genres where there is a strong parasocial connection to the author that drives a desire to simulate interaction.
For something factual or scientific/mathematical, I would not want to interact with a nondeterministic pretend version of the author.
To answer your question, no. I read a lot and frankly I've never wanted to discuss anything with an author. My relationship is with the characters in the book, not the author.
For non-fiction books there is so much information online that if I want to dig deeper I'll just Google or Chat it.
I've written two text books myself - very (very) niche books that sold in the hundreds of copies. (So very small). I've never had a reader reach out to discuss anything.
Yes, I expect there are people out there who want to correspond with authors. But I suspect a large fraction of them aren't "curious" but more want to demonstrate competence or whatever. I doubt an AI would satisfy them.
Yes, I think there is a market (however thin) for this, but reaching that market will be close to impossible. I would suggest either building this knowing you'd be the only user, or abandoning the idea.
Like I might want to ask the author of a book why he didn't cite a book that was cited by many of the books he cited, was relevant to what he was trying to say, particularly looking back 20 years later comparing his work to other works that followed it.
The answers to that aren't in the book!
I’d pay 15$ for a second book that had more details and explanations though.
AI still makes up stuff, not fun with books
I’d pay a premium for the works of authors who despise it, if it existed; I reckon this would be a signal of their quality.
AI≠ Inteligence= no growth
Purpose of books will be doomed if you use AI in them