R2 applicant, just received the call, too excited to write many things now...
Just two things for other friends waiting for Chicago GSB:
1. The Adcom might write an email to ask whether you are convenient to receive the call late at night, if you are in China.
2. Can ask questions when receiving the call, but I dont think we need to ask too many. Joanna said most details would be included in the offer package.