I sent the Assistant Dean of Admissions an email about this today and he responded with:
Congratulations on your offer of admission, very exciting!
Your offer should appear on OLSAS today, however, should it not, this email will serve as evidence your offer was last minute and we will honour our decision beyond the expiry date.
Please continue to check back and if you have any questions, please do not hesitate to contact me.
So I trust that he will get back to anyone else who emailed about this as well!! Congrats everyone