Flarum is definitely still under active development. If you click on 'Chat' in the menu at the top and take a look at Gitter, you will see that there is a lot of activity both in support and development.
The lack of announcements may be true however the staff are actually doing their best to get the ball rolling and preparing us all for a stable release. There are many of us here already that are on board and using the software for our own active communities and projects. Put it this way, even if the project was to be discontinued someone would surely pick up where Toby and Franz have left off. ?
I've learned to understand that just because I don't physically "see" something happening it doesn't mean it isn't happening in the background.
