After July 1, 1959, any insurer may file with the Commission a written notice of its election to comply with the provisions of § 38.2-3207 after a specified date before January 1, 1966. After the filing of the notice, then upon the specified date, which shall be the operative date of this section for the insurer, § 38.2-3207 shall become operative with respect to the ordinary policies thereafter issued by that insurer. If an insurer makes no such election, the operative date of § 38.2-3207 for the insurer shall be January 1, 1966.