(1) In general The plan sponsor of a composite plan shall not accept or recognize a collective bargaining agreement (or any modification to such agreement), and no contributions may be accepted and no benefits may be accrued or otherwise earned under the agreement— (A) in any case in which the plan actuary of any defined benefit plan that would be treated as a legacy plan with respect to such composite plan has certified under section 305(b)(3) that such defined benefit plan is or will be in critical status for the plan year in which such agreement would take effect or for any of the succeeding 5 plan years