I've mentioned Michael J Sullivan here before. I met him on wattpad and he's a very successful hybrid author, but mostly traditional.
He and his publisher just parted ways over audio rights to his novels. This is an interesting article on why (btw, Robin is his wife): https://www.reddit.com/r/Fantasy/comments/6f1v96/why_del_rey_and_i_will_be_parting_ways/
Now, then, we've heard rumblings that publishers are cracking down on requiring audio rights, but that they are also not willing to increase the advances to account for having them. It was important to find out what the value of these were so we could make informed decisions so we started shopping the various books I have "in the works" to a number of audio publishers and found out...they're worth a lot. Like 7-figures for thee (sic) books a lot. That's MUCH, MUCH more than my first "major deal" (and it was my first 7-figure deal ever). So...I signed up the books, as it provided me a level of stability that is hard to come by in this business. I did so knowing full well that it might jeopardize the print and ebook versions. But it was, as they say making me "a deal I couldn't refuse."
She [Robin] wanted to make sure Del Rey realized that the audio books were sold, so they knew what they could have and what they couldn't -- basically the same as the last contract. As you might have guessed, the response came back that the CEO at Penguin Random House has made a corporate wide decree that states, that editors with their imprints (including Del Rey) are "absolutely, and with no exceptions, forbidden to strike deals anymore that do not include audio rights."