>they should do it all at once

When I was last laid off, the meeting was concurrent with my friend on another team.

I was not laid off by my manager but my 2x skip; other members of my team were laid off, presumably at the same time, by someone else in our CoC.

So based on these observations, I think for security etc reasons you need to lay people off all at once in batches. Too easy for lag to create ‘insider/outsider threat’ situations.

Obviously my points are redundant if you just do it over email.