I worked at Yahoo in 2008 when they laid off thousands and yes every single person got a calendar invite and met in a meeting room 1:1 with a manager. It was difficult but they did it. Times definitely have changed.
Yes, people generally put two and two together when there was a calendar invite with their manager and HR.
We were in a European office though, so layoffs aren't American-style "escorted from the office with immediate effect".