So, it dawned on me after making this thread to try a different avenue of support. I just got off chatting with Playstation Network. The agent I spoke with said that because I pre-ordered the game from a 3rd party retailer (instead of digitally through PSN), the code I was given won't be valid until tomorrow morning when Early Access actually starts. She also said that it may not be immediately at 2:01 PST, either, as the codes will be updated on PSN throughout the morning.

I'm still not sure I understand how some people have been able to download the client already, but this explanation at least makes some sense. What I don't understand is why SE's support wasn't able to give a similar explanation.

I still would appreciate Square-Enix Support validating what PSN just told me since it's their game.

Lastly, it's worth noting I was on live chat support with the PSN agent in under 10 minutes. That's how Customer Support should be handled .