There is no great way to do it. If they told people in person, people would frame it as being humiliated and then forced to walk through the office with everyone knowing. If they did not warn people, they would complain about being blind sided. Layoffs are a terrible thing to go through and all things considered I don't think this was a bad way at all. No one had to do the walk of shame, everyone had a day or so to prepare themselves for it.

But that is just my preference, others would prefer something else. Everyone though would prefer not to get laid off. Unfortunate for all involved.

You can't when you're dealing with 6000+ people. Likely even the managers didn't know so as to avoid feeding the rumor mill. They'll now need to make up their minds about their reports whom they wouldn't mind losing.

Are you saying top executives selected 10% out of all 6000 employees without consulting their direct managers who to fire? That would be a random 10% sample at best. Obviously managers would be involved in deciding who is worth to keep or not.

No, I'm suggesting that managers might have been made to select them on the spot. I worked as a manager. This is usually a very easy question to answer unless your team consists entirely of rockstars, which I haven't experienced in practice. As a manager you are acutely aware of who's producing and who's dragging their feet.

No way are the managers going to all stay late on Friday and figure out who to fire on Saturday. Those discussions have already happened, and they know who is being let go.

This is Musk we're talking about here. He might have decided this over lunch a few hours before the announcement.