Layoffs are one thing, but to be cut off without any notice, that really sucks. I usually know months in advance that when I'll leave, so I'll have time to finish what I'm working on and train the people who will take over my responsibilities. It seems weirdly destructive for a company not to allow for that.
As for email, calendar etc, I think the lesson here is not to depend on anything from your employer. Keep everything under your own control, so you won't lose too much when you get fired.
Are you outside the US by chance? Sudden layoffs like this are the norm here.
I do live outside the US, but in another part of this discussion I was just taught not to assume that reports of unhealthy working conditions coming from the US represent the norm.