Re: I thought?
Yeah, pretty much. The only time that's not happened to me was when I handed in my own notice (due to a better job offer elsewhere). But for anyone I've worked with who's been let go, their access is immediately curtailed and they are removed from the premises. It's for their own good as much as that of the company's.
Happened to one of my managers a few years back shortly after a takeover (I was tasked with revoking his access whilst he went to the interview of no return). He took it fine afterwards and simply told me "It's a business decision, you can't take these things personally. You just have to accept them and move on".
One month later he had a much better job at another company anyway.