Anyone knows how much time on average does it take for a locked course to be realesed in beta?
I'd like to start the Czech course, but it feels like an eternity waiting for it to reach beta
Amongst other things, Duolingo needs to deploy the audio. I don't know the details of what this process entails, but it is evidently not simply a matter of flicking a switch. In the case of the Russian course, there were months of delay; in some other languages, it's taken less than a week.
In the case of Czech, I notice that HelpfulDuo has very recently updated the release date to the first of September, which I assume represents the DL staff's prediction on when the course will go live.