It might be a good idea, but I'm fairly positive now that it has nothing to do with the publishers.
I stumbled upon this thread:
https://www.mobileread.com/forums/showthread.php?t=8709
in which it states that Sony use an affiliate company to do the conversion. They charge for the service, quite a lot as it goes.
To my mind this makes Sony wholly culpable, as they contract those who make the conversion.