(1) Unless the articles or bylaws of a corporation specifically provide otherwise, the requirements of section 780 shall not apply to business combinations of a corporation that on the effective date of this chapter had an existing interested shareholder, whether the business combination is with the existing shareholder, with any other person that becomes an interested shareholder after the effective date of this chapter, or a present or future affiliate of an existing interested shareholder. However, at any time after the effective date of this chapter, the board of directors of the corporation may elect by resolution to be subject, in whole or in part, as to specifically identified or unidentified interested shareholders, to the requirements of section 780.

    (2) The articles or bylaws of a corporation may provide that if the board of directors adopts a resolution under subsection (1), the resolution shall be subject to approval of the shareholders in the manner and by the vote specified in the articles or bylaws.

    (3) An election under this section may be added to but may not be altered or repealed except by an amendment to the articles of incorporation which was adopted by a vote of shareholders pursuant to the requirements of section 784(1)(b).