The commissioner shall not authorize a domestic mutual insurer so to extinguish the contingent liability of any of its members or in any of its policies to be issued, unless it qualifies to and does extinguish such liability of all its members and in all policies for all classes of insurance transacted by it. Except that, if required by the laws of another state in which the insurer is transacting insurance as an authorized insurer, the insurer may issue policies providing for the contingent liability of such of its members as may acquire such policies in such state, and need not extinguish the contingent liability applicable to policies theretofore in force in the state.