Public employees shall have the right to self-organization, to form, join or assist public employee organizations, to bargain collectively through certified employee organizations of their own choosing and shall have the right to refrain from any or all of such activities. However, neither managerial nor confidential employees shall constitute or be included in any bargaining unit, nor shall they have the right to bargain collectively; provided, however, that public employees shall be presumed eligible for the rights set forth in this section, and no employee shall be deprived of these rights unless, as to such employee, a determination of managerial or confidential status has been rendered by the board of certification; and provided further, that nothing in this chapter shall be construed to: (i) deny to any managerial or confidential employee his or her rights under section fifteen of the civil rights law or any other rights; or (ii) prohibit any appropriate official or officials of a public employer as defined in this chapter to hear and consider grievances and complaints of managerial and confidential employees concerning the terms and conditions of their employment and to make recommendations thereon to the chief executive officer of the public employer for such action as such chief executive officer shall deem appropriate. A certified or designated employee organization shall be recognized as the exclusive bargaining representative of the public employees in the appropriate bargaining unit.