I actually understand many of the reasons why companies need to let people go. Sometimes it really does make sense to stop having someone as a full time employ

I actually understand many of the reasons why companies need to let people go. Sometimes it really does make sense to stop having someone as a full time employee. But if that person did anything significant during their employment, chances are the company might need a little of their time again in the future. That extra, on-demand time should be compensated well; and the possibility of such a need should be discussed before the exit.