(a) The provisions of AS 39.20.500 - 39.20.550 do not affect any other provision of law relating to sex discrimination, pregnancy, or parenthood.
(b) The provisions of AS 39.20.500 - 39.20.550 are subject to collective bargaining. However, except as provided in (c) of this section, a collective bargaining contract that does not contain benefit provisions at least as beneficial to the employee as those provided by AS 39.20.500 - 39.20.550 shall be considered to contain the benefit provisions of those statutes.
(c) The commissioner of education and early development may approve a collective bargaining agreement entered into between a school district or a regional educational attendance area and a bargaining organization representing certificated employees that does not meet the leave requirements of AS 39.20.500 - 39.20.550, if the district or attendance area establishes to the satisfaction of the commissioner that a variance from the requirements of AS 39.20.500 - 39.20.550 is necessary to avoid a hardship on the school district based on the lack of qualified, available substitute teachers to replace teachers on leave under AS 39.20.500 - 39.20.550 or the lack of available housing for replacement teachers who do not live in the community.