If you can tell what is missing it can be tagged as rc like right now
There is not a date for release really. It is like the egg and the chicken type of game. People don't want to use it as beta, therefore, no one is trying it out and reporting bugs if any. As no one reports anything, we can not tag it as release.
Have you try it?
The only thing I can tell is that there are a quite a few sites already running it in production.
We have the beta installed on our test moodle, and have installed the script and bbbevents on the BBB server. Could you let me know which log in moodle the engagement is sent to?