From what I understand, there is still no official info on this.
I've spent many hours in Alpha and doing the same in Beta. While it is true we are testing this code at our own free will, I would prefer not to level up for the third time.
While thoes 8 levels wouldn't hurt day one players that were not in the Beta, it would still be a nice symbolic gesture and reward for the rest of us here.
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There's always a big chance that the beginning will be different. As someone who does this sort of thing myself I wouldn't want anyone to miss the changes I put in my game and since this is a Beta 2 months from the launch date the changes might be small or really big depending on how fast Bungie can work but there will still be changes.