I wholly support this answer. I will add a caveat - I'm mostly OK if Audible is proactively paying the author (and the voice actor(s), director, sound engineer

I wholly support this answer. I will add a caveat - I'm mostly OK if Audible is proactively paying the author (and the voice actor(s), director, sound engineer, et.al.) to create a work that would not normally exist. There's no indication that this is the case with most of these exclusives.