The high school may have been sprinklered, but don’t remember if it had voice evac. If it did, probably just the Gym and Auditorium. That seems to be the norm around here anyway, voice evac only required in the portion of the school considered an “assembly occupancy”. I know a couple of the elementary schools in the district were not sprinklered and did not have voice evac systems. Yet they had the pull stations omitted from the exits.
Bottom line is this, the AHJ can do whatever he wants! And local codes and ordinances can and will always trump NFPA or any other national standard. The AHJ can be anyone from the State Fire Marshal, local Fire Chief, mayor and/or city council, etc. And lets not even get into insurance company requirements! I’ve seen insurance companies require some pretty silly stuff that make the local fire chief say to himself WTF!
This is the wording from the state level of fire codes: The State Fire Marshal may accept alternatives to specific systems, conditions, arrangements, materials, or equipment required by these Regulations. Such alternatives shall afford an equivalent level of fire safety, in the opinion of the State Fire Marshal. Notice the “in the opinion” part? In his “opinion”, he could simply think there is a benefit to installing smoke detectors or sprinklers above a suspended ceiling - and now you are installing smoke detectors or sprinklers above a suspended ceiling.
And this is how the local AHJ has the right to “change” the code: Each of the following Codes and Standards, published by the National Fire Protection Association… are hereby adopted in their entirety with the exception of any changes, additions or deletions as listed in Annex B of these Regulations…