The provisions of subsection (a) of section 4a-2, subsection (a) of section 4a-12, sections 17b-137, 17b-179, 17b-745, 46b-172, 46b-207, 46b-208, 46b-215, 46b-218, 46b-231 and 46b-235, subsection (a) of section 51-348a, subsection (d) of section 52-50, sections 52-259a, 52-362, 52-362c to 52-362f, inclusive, and 53-304 shall not be construed to alter, modify, impair or change existing collective bargaining agreements, any bargaining unit designation, award, settlement, benefit, existing employment practice or classification of any employee in the event of transfer from one division, bureau or agency or department to another division, agency or department.