(1) Where a party sues or is sued as executor, administrator or trustee:
(a) it shall not be necessary to join as a party a person having a beneficial interest in the estate or under the trust; and
(b) a judgment or order in the proceeding shall bind all such persons as it does the executor, administrator or trustee.
(2) Subrule (1) does not limit the power of the Court to order the addition of a party under rule 9.06 or to make an order under rule 16.01(2).