There are a few conditions that do require a link in that way but not as many as used to be true since the is-event-true-delay can now be used instead by supplying the optional 3rd argument.
I think that can only be used to control when the directive is satisfied. You still need a chained event to control when it shows up, unless it's a simple type that the game recognizes.
I ran into a situation once where the directive wouldn't work correctly no matter what I tried (the "run away" one in the fifth PI mission, which shows as completed right away when it appears). I must have played with that for hours and tried all manner of chains and variables, but finally just gave up on it. In hindsight, it was probably a waste of time for something that small.
