There might be one more batch of acceptances this month, since someone in the last interview group posted that they were told that there were enough spots for each of them, so there should be <10 spots open assuming that a few people in that group were accepted.
Timeline from last two years based off the Mayo threads:
First week of March - creation of alternate list from the people on hold. ~100 people are rejected, ~100 are put on alternate list
Very little (if any) movement until...
Early May - Big alternate list movement
The amount of waitlist movement will be influence by the amount of acceptances they give out before formulating the alternate list. Two years ago, they gave out 48 initial acceptances for 42 spots. Last year, it was 47 initial acceptances for 42 spots. Each year, ~20 people came off the alternate list.