For any petition filed with the regional superintendent of schools under this Article prior to the effective date of this amendatory Act of the 100th General Assembly, including a petition for a rehearing pursuant to subsection (n) of Section 7-6 of this Code, the proposed action described in the petition, including all notices, hearings, administrative decisions, ballots, elections, and passage requirements relating thereto, shall proceed and be in accordance with the law in effect prior to the effective date of this amendatory Act of the 100th General Assembly.