The reason for the beta was to test server stability, scale and ov we rall stability. That's what betas are for. (At leat ours)
Usually how it works is that we branch very early which means that most of the game isn't ready, functional or tweaked so we turn most of the features off. Then we stabalize a subset of features that we feel confortable with so people playing the beta can still have fun but it's not representable of the release version at all. This is all done to gather information so we can tweak, fix bugs, and load balance the final release so we can have rhe smoothest/best release possible