(1) In addition to approval in accordance with RCW 23B.11.030, a plan of merger or share exchange pursuant to which a social purpose corporation would not be the surviving corporation must be approved by two-thirds of the voting group comprising all the votes of the corporation entitled to be cast on the plan, and by two-thirds of the holders of the outstanding shares of each class or series, voting as separate voting groups, and of each other voting group entitled under the articles of incorporation to vote separately on the proposed plan. The articles of incorporation may require a greater vote than that provided for in this subsection.

(2) The additional approval described in subsection (1) of this section is not required if the surviving corporation of the plan of merger or share exchange is a social purpose corporation governed by this chapter and includes a specific social purpose or purposes that do not materially differ from the disappearing corporation's specific social purpose or purposes, if any.