Modification of the terms of the power of attorney and subscriber’s agreement of a domestic reciprocal shall be made jointly by the attorney and the subscribers’ advisory committee. Any such modification shall be filed with the attorney and the Commission and such filing shall by operation of law bind all subscribers the same as if each subscriber individually adopted and executed the modified, altered, or amended subscriber’s agreement and power of attorney, and a copy of such agreement and power of attorney shall be provided to each subscriber within ninety days of such modifications, alterations, or amendments. No modification shall be effective retroactively, nor shall it affect any insurance contract issued prior to the modification.