Source

While we can register the cd key's already, if you have purchased a digital download from the SE store, these codes will just be like in HW send out, or made available in the NA store at midnight (June 20th) since that's the official release of the game. People that have bought a physical copy from somewhere and had them delivered already, or bought digital from somewhere else and have gotten a code already, are now able to register their full product as stated in the instructions above. Just be patient you will receive your code by tonight the latest.

You will have till June 23rd to register that additional code/key to your service account.