In addition to what Ben mentioned, OTA had blockers as mentioned previously.
The last push on the OTA was a manual push done by me, to fix notification and turn off the forced data collection for the dogfood builds so that you can opt to now have data collection on.
To note, the people in the dogfood had signed an agreement to have data collection on. We have now reliquished that obligation. There was some other things too that was mentioned in a prior talk about the dogfood program. If you weren't in the dogfood program, there's no need to worry about what that stuff involved. I think George Rotor sent out that email. Maybe it was Valetin.
You can continue to build the open source B2G OS from master yourself to update your Flame, but there are no further commercial releases of Firefox OS planned for that device as it was a reference device for Firefox OS smartphone development. There is an ongoing Transition Project to transition the open source B2G OS to a new more webby architecture, and transition the smartphone specific components to community ownership.