Both thebehavior of the forces on theground and of their commanders in Cairo indicates that if the Egyptian military is permitted to deploy its forces to the Sinai, those forces will not serve any helpful purpose for Israel.
Similar behavior exists in herds of caribou that migrate across the Arctic coastal plan to a specific calving ground even though it is unlikely any of the individual animals know where they are going.
Parents establish rules and modes of acceptable behavior as a training ground for children, so that when they eventually make a transition into the world, they will be accustomed to behaving in ways deemed socially acceptable.