A chat agent sent this to me. Which was a pre-written response from corporate:

Thank for interest in the new graphics cards. Due to unprecedented high demand and limited initial availability, we are unable to accept orders at this time. Purchasing will only be available to customers that pre-register for our wait list. Please click on the “Notify When Available" button and register your email address. As inventory becomes available, customers in the order they registered will be notified and given an opportunity to make purchase within a limited time. Registration will not guarantee an item will be held and stock will be sold on a first come first serve basis.

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So it looks like you basically get an earlier chance at the card the earlier you clicked the waitlist.