I've worked for multiple companies that have had major reductions in force at times. When folks get laid off in a group, it has never been done 1:1. Usually the group getting let go is told all at once separately from the rest of the company. It's done per team or per department, so if you're a software engineer getting cut, you're told at the same time with the other software engineers getting cut, but yes usually the guy that runs the department will be present.