Can't say for sure but the link explains it:

[...]- Three registration codes obtained from the product or the "FINAL FANTASY XIV Service Center" [...]
*The "FINAL FANTASY XIV Service Center" website will be available after the game is launched. Please note that the website can only be accessed by those who purchased FINAL FANTASY XIV and registered a service account.

So, I think you'll be able to set it up only after the launch. I was hoping they would allow it for EA, but I think it will be only on the 27th

~P