The only news I've heard of this, besides here of course, is a self-published author being upset about it on Twitter. She is worried about it taking money from authors if people don't have to buy the e-book version to go along with the audio and said there hadn't been consent to this, which she finds problematic.
https://twitter.com/kj_charles/statu...31163821727749
I understand her frustration and agree with the way she puts it. The legalities must allow this, I'm assuming, since I doubt Amazon/Audible would have snuck this in illegally without doing thorough research that it was okay to do otherwise.