My layman’s Understanding is that admissions team tries to increase the yield and have some fun and enjoy meeting candidates so they call as many as they can.
They also realize that some folks are in a tricky time zone so they send a Zoom link to those folks the sort of catch them all at the same time.
Still, Some people simply get an email and then some admitted candidates get nothing and just find out that they got admitted on the portal because somehow they fell through the cracks. This happens every year.
so if you don’t get a call and you don’t get a zoom invite, there is still a small chance that you’ll get an email or a portal update but that means you will get to wait the longest and stress the most 😞
PS. This has happened with both domestic and international candidates.