There is no parallel universe in which computer-generated text-to-speech compares with a real audiobook. The Authors Guild should pick their battles more carefully, because nobody is going to care about this stupid feature.
I haven't heard this new computer-generated voice, but surely Amazon's going to iterate and iterate and iterate until it's "good enough" to disrupt the audio book market.
They'd stand just as good a chance taking sheet music and lyrics and iterating and iterating and iterating until it's good enough to disrupt Warner Music Group.
Well, consider bands and production houses that use MIDI recreations of well-known music instead of purchasing the rights to the actual recordings. It's not good enough for most uses, but for some, it certainly is.