I've googled over the internet, still can't find an official answer. I can see I can make build glance scenes, but those are "hidden" one swipe away from the user beneath actual watch face.
Are developers allowed to publish watch faces?
No, it is not possible. In the Apple WatchKit forums, an Apple evangelist links to this thread for the FAQ on creating a custom watch face.
https://devforums.apple.com/thread/254629?tstart=15
Here is the link to the "official" WatchKit FAQ https://devforums.apple.com/thread/254675?tstart=0
Technically, you could create an app that is a watch, but it wouldn't be a watch face.