I'm expecting beta to be delayed, really. Or for it to be much more alpha - quality than usual. To be a true beta then it would need to be a fully integrated set of all game systems, each of which need to go through alpha first. Sounds unlikely in a month, especially considering the Xmas break.
Remember those alpha builds are produced to nail down core concepts of the game, not to do overall testing. So we actually don't know any internal schedule FD have for this. It easily could be that beta is already built slowly in background of all this, and when all configuration and feedback is nailed down, it will be fed into that.