This guarantees that a large percentage of people are going to learn about it through other employees rather than from their managers though.

Not necessarily. A humane call with, "Please don't discuss this until 4 pm, as I want to tell people personally" would go a long way. And if people do talk about it, you can still have the rest of the discussion, which is not just about revealing facts.

This is equally true for in-person layoffs done as individual meetings, which happen all the time.

True, but they can try to make both the recently laid off and soon-to-be-laid-off employees be too busy to communicate, or they can round up the ones who will be staying so at least they don't pass around the news to those who aren't going to be laid off before they know they're not on the chopping block.

In a remote layoff situation? The whole company would know the moment one person was laid off.

No, in an in-person layoff situation. I was addressing the comment I replied to where it said "This is equally true for in-person layoffs".

I've been in an office during an in-person layoff situation (surprisingly only once during my 15+ year career), and they were definitely taking advantage of it being done in person.

What potential problems could this cause?

Maybe a disgruntled employee takes down your database or copies confidential info onto their personal computer

Your notion is that nobody who has ever been laid off had a idea it was coming? And you want to build your security with that foundation?

No.

In that case I don't think your previous comment makes much sense.

I layed of 7 employees (mandated closure of non-essential business) and we called them each individually over FaceTime to do it.

That's noble, but seven doesn't really scale to "hundreds" especially if you are wanting the news to break more or less uniformly across the group you are laying off.

Father was furloughed along with 900 others.

Every manager called every single worker personally to relay the news, for a general well-being check in, and to answer any questions about UI benefit filing. Each manager has also personally checked in once a week to see how things are going, and to provide updates, and said they will continue to do so for the next 5 weeks they plan to be closed.

... and that's a non-union, publicly traded company.

If a company only has one manager for "hundreds" of employees, this has to be very low on the scale of the ways the company is doing badly for its workers.

The only way is face to face. If you can't do that then you are shit. Video? Really?

I've been an employer for 20 years. They come and go and quite right too. I encourage my troops that if they are looking elsewhere then we'll give them time off for interviews and assistance in how to interview effectively. I really am not joking. If you think you own someone completely then your name is Satan! I just want a decent day of work out of you, when you want to work for me. If you no longer want to work for me then I want to get rid of you as efficiently and as fairly as possible ...

Reminder: The world has a bad case of pandemic. The reason for layoffs is the extreme measures society has been taking to avoid unnecessary face-to-face interactions. One thing that would piss me off more than being fired is catching a disease from the person firing me.