I had my waitlist call as well (Domestic)
It was a relatively quick call, she gave a brief overview of the waitlist process and then gave me feedback on my application (I had no actionable items, she said I had a great application & interview but low undergraduate gpa). I asked about the waitlist timeline and she said there won't be any applicants coming off in December, but perhaps a few in February/March. Majority will be coming off in May/June once R2 deposit deadline has passed.
Hopefully this helps manage others' expectations this year and next.
Best of luck everyone!