I pre-ordered and am currently enjoying early access and I know early access is a perk of pre-ordering. However, personally, I think that if someone has physically received the game already, the entry of their game code should allow them into early access. Having the game in-hand and not being able to play it just doesn't seem right to me.
They only have the game because some companies decided to send them out early. Which normally is a big no-no. I assume this has to do with BIoware's decision not to allow a grace period.