On and after the effective date of this amendatory Act, the provisions of Sections 6-3, 6-4, 6-5, 6-10, 6-11 (now repealed), 6-12, 6-17, 6-18, 6-19, 6-20, and 6-21 of this School Code shall have no application in any educational service region having a population of 2,000,000 or more inhabitants.