I hate so much that this has a 100% chance of happening. Narrator can make a mediocre book shine, or make a good book into a fucking rollercoaster (Andy Serki's anyone).
AI is not a great narrator. Its character voices are boring, intonations weird, pacing awful. Why would anyone listen to a much worse version of what they could have with a human? I'd rather get amateur narrating it over an autocomplete trying to sound like Morgan Freeman.