Hy Hellomrwilson, as a famous GM engineer once said "Parts left out cost us nothing, and cause us no service problems", what he meant was, if a part was on a vehicle the manufacturer of the vehicle felt that part was required for the vehicle to operate with no problems for the majority of users of that vehicle. The exhaust flapper was designed to send some heat up to the intake manifold when the engine was cold, this would hopefully prevent carburetor icing. As the engine/manifold warmed up the bimetal spring on the butterfly shaft opened the exhaust flapper to allow a more unimpeded exhaust flow. Personally I wouldn't remove the valve from the exhaust manifold, hope that helps.
