We’re still 5 weeks out, and even on yesterday’s stream they talked about new changes that were recently added to the build they were on (like adding new traits to heroes). It’s still very much in development and flux.
That’s not to say they can’t do as @Dejin suggested and have a big ongoing game of course, but I also suspect they might be trying to show off all 6 cultures before launch. I believe this makes three we’ve seen.