I was definitely waiting for this release! Was reading through the discussions on github a couple of weeks ago because of an annoying bug in version 0.15.12 and found out that it is supposed to be fixed in 0.16.
I'm assuming you mean the jellyfin server and not the Android TV client specifically.
Running the jellyfin server on an SBC is possible, I'm running it on a pi 4 right now. Personally, I'd recommend installing docker and running the service in a container. There's official docs for how to do so https://jellyfin.org/docs/general/installation/container/
That being said, Jellyfin docs recommend against running on an SBC. I too, running it on an SBC, recommend against it. It can do the "happy path" well. But if the stored media is in a format that requires the server to transcode it for the current, it cannot handle it. The time it takes to transcode is several times longer than the actual run time of the media. You will have a bad time. I'm currently looking to change/upgrade the hardware to work around this
Fire TV is Android TV so yes it will also get the update! Unfortunately Amazon rejected the update like they often do so it will take a bit longer before the update is available on the Amazon Appstore.