The service type is set by the dealership. They leave the factory on long life, but some dealers switch them to annual if the PCP or lease is on a low mileage agreement.
That was told to me by the service manager at my local Audi dealership. Obviously whether this happens depends entirely on the individual franchise and whether the expected mileage is known.
You can, and I have, ask them to set it to your preferred service schedule when they do the PDI.