on a personal level I was hired (by Microsoft, my first and only "big tech" job) in April 2020 and I am still working here... all these companies "over-hired" during the pandemic, and the term "covid hire" is even a thing..
Overhiring implies that MSFT's headcount went down over this time. But that doesn't seem to be the case. They still hire a lot, just not in North America.
I remember interviewing someone who got hired by Facebook, sat around for a few weeks for a team to open up while they went through onboarding / Junior training, then was let go.
COVID did weird things to the industry, that's for sure.