The hole in the lid flap will probably serve to lead out of the camera hand strap, but then you do not get even the camera out of his pocket. Suppose you have the camera velvet bag dangling at the wrist and one encounters a possible photo opportunity. Then you need only pull the hand from the wrist strap, carry the hand strap back through the hole and take the camera out of his pocket. The possible subject is then probably long gone. Then there is the risk that you drop the camera that yes, at least temporarily no longer depends on the wrist strap.
Therefore I run the camera wrist strap always easy sideways out of his pocket, whether the belt, wrist, or in their luggage. What remains is an unnecessary hole in the lid, through which it can not possibly also into rain.