I generally agree with you and the parent on this. It definitely is self-fulfilling. Because some companies cut access to laid off employees immediately, it makes the others look negligent if they don't. I'm not trying to say I think this is correct or the best, just trying to speculate why some employers choose to take this action. Certainly all don't, but it does seem more common the larger a company gets.

I'd be curious if every laid off Google employee experiences this hard cut off, or if it's determined case by case.