I agree with you that it is weird to send addmission emails in the middle of the night. Even if they were automatically sent, the WWS should set a more appropriate for the system rather than sent some emails at 12:01am and them some more at 3 am.
I am international applicant. I learn from previous posters that international applicants will receive information via email. If tomorrow I still not heard anything from the GSPP, I will assume that I am rejected. That's so sad .
By the way, congratulation to those who are already admitted, and good luck for the rest.