Yes, it's to provide a flow of cooling air to the AC condensor (radiator) even if the car's stationary.
This can be a handy quick and dirty check on a used car actually. If it's a somewhat cool day it can be tricky checking the AC is actually working and therefore, has pressure. If the fan is cutting in, that normally suggests the AC system has enough internal pressure to at least not be blocked from working so at very least is prob O.K. to take a regas service.
This is especially the case on A2's as the compressor centre rotates all the time on our cars, so no visual tell-tale there to see if system's cutting in.