No Digital Early Access code?

[Causality]

Codes will not go live till closer to the early access date

A CSR actually said this is untrue and it can be used right away

Greetings,

Pre-order codes are redeemable right away from the Heavensward pre-order sites:
North American Heavensward Pre-order site
European Heavensward Pre-order site

Once there you can redeem your 18-digit code you received when pre-ordering (AAAAAA-123-AAAAAA-123) and select the platform you wish to receive an early access code for. (If you pre-ordered from the NA SE Online store, then your pre-order code can be found by visiting your Square Enix Online Store account page. Click “My Account” at the top of store page, then click “Your Orders”. Your 18-digit Pre-order code will be displayed along with a button labeled “Instructions” on how to redeem it.)

If you're receiving an error saying that your code has already been used, then please contact the Square Enix Support site for your region (NA/EU) and let them know of the issue, and the code that you received, so they can investigate it.