I did not realize when i purchased my four Sonos Ones, a Sub, and a Beam that Alexa would not be able to read Kindle books!
Then, lo and behold, I searched this community and found multiple topics created on this subject, but with very little input from Sonos support staff or from devs. It seems this was promised more than a year ago, and yet with the lack of enthusiasm for this among the Sonos team, I don't see how this will ever happen! The community itself is enthusiastic enough about it, as a quick search brings up numerous threads such as this one:
The Sonos team gave an initial response, but when numerous other members chimed in with their requests for this service, the team fell silent.
It seems I am not the only one who is unpleasantly surprised that their brand new expensive Sonos system cannot read Kindle books. I appreciate that it can now (finally ...) read Audible books, but at the moment I don't want to shell out for an Audible subscription. I have Amazon Prime, and Kindle books support would suit me just fine.
Devs, please stop promising this and make this a true high priority. Thank you.