In the past, how long have Up-to-date OS upgrades taken to arrive?
This appears to be a real issue, per this MacRumors article from earlier today:


  Apple support staff have acknowledged the difficulties and are advising customers that they may need to wait up to three days to receive replacement codes, although some replacement codes are reportedly already coming through without any action required by the users.


Hopefully your codes will arrive within that window - if not, I recommend you contact Apple support; given proof-of-purchase on your MacBook, they should get you sorted.