Mass. Gen. Laws ch. 211B, § 10C

The general superintendence and administrative authority of the chief justice of the trial court, court administrator, and the chief justices of the respective departments of the trial court and the first justices of particular courts shall not include the authority or power to exercise, supersede, limit, prevent the exercise of or otherwise affect any of the powers, duties and responsibilities of the clerks or registers of probate in any general or special law, including laws authorizing or governing the selection and appointment of personnel, except where expressly authorized.