My new Fire TV 3 arrived today and I plugged it into the HDMI port on my amp. I own the old Amazon boxes so it was easy to install. It is Atmos ready but, unbelievably, there is no Atmos content available on Amazon yet. Also, if I go to Netflix on the new Amazon box, it plays Okja in 5.1. If I watch Okja via my Xbox One, it plays in Atmos.
I rang Netflix and they said they have no plans to enable Atmos on the Fire TV. Crazy.
I am disappointed with this new Amazon box because of this.