No, there is no such explicit requirement in the Regulation. This depends on the service provided. If Air Traffic Control (ATC) is only provided with the use of surveillance equipment, there is no need for the ATCO to also hold the procedural rating, e.g. for applying vertical separation in emergency situations, this should be part of the ACS training. If the contingency plans also include procedures for service continuity by means of providing (limited) procedural ATC, a procedural rating should be required. It also needs to be taken into account what applies for the maintenance and revalidation of the unit endorsement.