The only scenario I could imagine is a narration language where Audiobooks didn't exist so far for economic reasons (i.e. low population). Digital narration could bring down production costs to the point of making it economic, basically creating the audiobook market for this language.

But then, if the narration is bad (which it likely is because TTS is worse in minor languages), I don't know how many users could be converted to pay a premium for a better human narration. Also here I think it's more likely that funding will be used to improve the narration engine as a whole instead of going back to hiring humans and renting a studio for each book...