That's just an OEM replacement part.
Those things can break/malfunction. I've seen one where the bypass valve was missing one of the rivets that connect the body of the valve to the mounting plate. This allowed the valve to move when the rod was actuated, putting further stress on the remaining rivets. The diaphragm inside the valve can also rupture, or the rod can get bent, etc, etc.
Unlike a turbo, the bypass valve (aka wastegate, on a turbo) does not control the amount of boost the S/C puts out. That is determined by the size of the pulley. The only reason to replace one, other than physical damage, would be if it was leaking around the valve seat, which would reduce the level of boost.
