Nothing in sections 7-467 to 7-477, inclusive, shall constitute a grant of the right to strike to employees of any municipal employer and such strikes are prohibited. In the event an agreement expires before a new agreement has been approved by the municipal employer and the employee organization, the terms of the expired agreement shall remain in effect until such time as a new agreement is reached and approved in accordance with section 7-474. Nothing in this section shall affect the rights and duties of the municipal employer and the employee organization under sections 7-468 to 7-470, inclusive, during the period of time such expired agreement remains in effect.