NFPA Code versus the Law
It's important to understand the difference between the publication "NFPA Code" and the law. The NFPA Code is a publication produced by the National Fire Protection Associating, a non-profit publishing house. As such, the NFPA 72 Code is a suggestion or recommendation on the minimum standards for a fire alarm system. A Law or Mandate is totally up to the government. Usually governments say "We will use the NFPA Code" as our law. That's where a mandate comes from, not the NFPA.
Somewhere in the NFPA Code, the Code does say to use the air duct smoke detector that is next to the damper to shut the damper, and the Code does say to use the air duct smoke detector at the air handling unit to shut down the fan. More stringent may be the building owners, the insurance company, the building's architect or design engineer, these Authorities Having Jurisdiction (AHJ) may want more devices to shut down the dampers and fans.
I've seen a lot of fire marshals say that anytime there is a fire alarm, all the dampers and all fans shut down. Sometimes, they'll even watch the dampers and fans to make sure they shut down on alarm. To me, that sounds like a good idea. Keep in mind that the fire marshal is the representative of the government, what the fire marshal says, goes.
These AHJs make the decisions on what is to be done with the dampers and fans. If the AHJs, including fire marshals, building inspectors, architectural engineers, insurance representatives, etc. don't enforce the shutdowns, it usually won't be done.
See Just Who Is the Authority Having Jurisdiction (AHJ)?
for more information on just who is the AHJ.
Unfortunately, for you, it's probably the building owners that are the ones that decide to make improvements to the fire alarm system, or not. The fire marshal really has to deal with a grandfathered building; for the fire marshal to require changes, the building owners would have to pay.
The testing isn't that expensive, but still, someone has to be convinced because testing the dampers and fans can take 5% to 50% longer to test, and that does cost money. Only a few building owners are willing to pay the extra inspection costs.