I'm assuming we can tell that the code is out when these threads die down, and cease to be made. I mean, there really isn't a need for a post on the beta when the beta is already in progress. Seems like the logical thing to me. At the least not a thread with its whole basis seems to be advertising the Beta. But I could be wrong, the sign-ups are closed and these threads are still around.
Along with that people will be too busy actually playing the beta to be bothered to post
The short beta could be a good thing, keeps people from whining about bugs and saying that the bugs ruined the entire game when it officially releases.