§ 1527-c. Shared superintendent program. Notwithstanding any other provision of law, rule or regulation to the contrary, the governing board of a school district with an enrollment of less than one thousand students in the previous year shall be authorized to enter into a school superintendent sharing contract with no more than two additional school districts each of which had fewer than one thousand in enrolled pupils in the previous year. Each shared superintendent arrangement shall be governed by the boards of education of the school districts participating in the shared contract. Provided however, that this section shall not be construed to alter, affect or impair any employment contract which is in effect on or before July first, two thousand thirteen. Any school district which has entered into a school superintendent sharing program will continue to be eligible to complete such contract notwithstanding that the enrollment of the school district exceeded one thousand students after entering into a shared superintendent contract.