This article shall not apply to managerial appointments that took effect prior to January 1, 1984, or in subsequent appointments, except that it shall apply when the provisions of this part and board rule would have required the employee to serve a new probationary period in a subsequent appointment. Where service of a new probationary period would have been discretionary on the part of the appointing power, the appointing power may either apply the provisions of this article to the new appointment, or require the employee to serve the probationary period previously prescribed for the class by the State Personnel Board, or appoint the employee with no new probationary period.