At least in outside communication, a year ago Mozilla only said they are shifting Firefox OS from phones to other devices and IoT [1]. Then they went on to do some smart TV stuff but were looking at other applications as well.
A single-board computer running Firefox OS was discussed last year here on HN. The post itself is now private. I think this was the demo, where they showed how to blink a LED from some HTML and Javascript:
[1] https://blog.mozilla.org/futurereleases/2016/02/04/next-step...