Did that person ever receive an A? A few schools last cycle extended IIs into March and April because they were slammed with the surge in applications and never quite caught up from the delays at the beginning of the cycle as they learned how to work around COVID.
A lot of people thought virtual interviews would cause people to hoard As, and that there would be a lot more WL movement than usual. That increased movement never manifested.
I always thought schools interviewing that late were just padding their WLs out of an abundance of caution. I never took the time to try to map people reporting late IIs to people later reporting As, so it would encouraging to hear that your friend's late II was more than just insurance for the school.