In the beginning I agree with the take then release method, but as your horse gets more educated and more advanced, if you are constantly taking pressure and dropping your reins or "giving them", then there is no stable place for your horse to push into the bridle. He will always wonder where it is he needs to be until the rider is able to maintain soft, even contact with the reins and allow the horse to reside comfortably, knowing where he is supposed to be.
In the beginning stages you teach them to give by immediately releasing, and repeat billions of times. There has to be somewhere for your horse to go to. Somewhere that is always the same, and always appealing.