I’m not sure what purpose that serves. Soccer is the dumbest sport of all in that regard. Only the referee knows how much time is left on the clock.
I could see it being useful in that if a team doesn’t know how much time is left, they won’t take a knee and actually will have to try to be aggressive and get a first down.
You could make it so several people know the time, as a check and balance, to make sure not only one person is aware of the time.