I have seen it on more than one place. Interestingly, all those places are research-focused universities. (And no, mere research institutes don't seem to enable it.)

In retrospect, it is quite obvious why that happens. Just for a start, if your place is such that a high-level executive announcing a layoff would lead people to believe in him, instead of reacting like "what is he talking about? is he crazy?", then you have no chance of ever getting productive water cooler conversations.