Sources: D’Ettorre (2001) in Regnier (1971)
Propaganda pheromones appear to be an emergent property of alarm pheromones which are released when an ant is attacked and that have evolved to alert other nestmates to the danger sot that they can flee or attack the invader.
Certain species of ants rely on stealing larvae from other ant species. They raid colonies and spray massive amounts of alarm pheromones as they do. The pheromones overwhelm the attacked colony workers & their flee response causes them to attack their own nestmates.
The attacking ants then steal the larvae and take it back to their colony where, once they are born, they perform worker functions for the nest - a function the attacking ants can’t do! Amazing that these ant species evolved this elaborate system, but this aspect of the system is less interesting outside of the context, I think.