Deadlines are just lazy management, we feel we need to set deadlines to motivate people and drive delivery, the problem is that the motivation is built on fear and are very poor at actually achieving quality outcomes.
One of two things is likely to happen with deadlines as your main motivator (a) they are ignore completely with very little impact on a workers motivation, this is likely a very disengaged workforce or (b) they are feared and drive an individual to try to hit the deadline not matter the cost either in quality or their well being, both are ultimately bad in the long run. Also we're also susceptible to Student Syndrome [0] which can exasperated scenario (b).
I believe that we are constantly stuck in rewrite cycles because we are forever rushing to meet arbitrary sprint deadlines.
Leadership should be using development metrics to try to estimate delivery velocity and understand the selected priority order for delivery, but don't turn those into deadlines, keep the system in control so that you can be accurate to your projection.