I say with great respect that sometimes a top level manager leaving is a great thing. It often turns out that entrenched management holds everyone back. When you get new blood and a new view often there can be a break through that otherwise wouldn't be possible. Top leaders are almost never fired unless there's a scandal. They will 99% of the time leave for new opportunities or be promoted out of that position because their talents are needed elsewhere. Good terms or bad you will never be able to tell unless you're on the know. That's the nice thing about being up at the top.