Parcel with township hall and maintenance building; reconnection to adjacent township. Any parcel of land owned by a township on which both a township hall and a maintenance building are located and that consists of the entire territory that was annexed by operation of law to a city coterminous with a different township under this Article shall, on September 1, 1988, be disconnected from the city and its coterminous township and reconnected to the township from which it was originally disconnected.