It also gets the owner back in the dealership to look at all the shiny new models while they wait for their oil change - a certain percentage of whom trade their car in, buy accessories, or detailing. There is still no substitute for having the customer at the dealership as often as possible which is why the old 30k mile comprehensive service has been broken down into more smaller services.
The service came out in 2012, 2 years after the 458 had already been released. If you go into most dealerships, you will notice that there aren't too many New cars with the exception of the California T. The cars you see are "used" since that has always been part of the game, buy new at MSRP and sell low mileage used at above MSRP so someone can have the latest NOW, try getting a new 488.
The service warranty really doesn't cost Ferrari much of anything and it allows the mechanics to inspect that vehicle with recommendations for non warranty service where they can make money (Check on price to replace battery on 458 - Battery not covered by warranty unless the car is driven over 2K miles annually) but for someone buying a used car, helps maintain value.
I suspect that ALL Ferraris are maintained per intervals in the US and no one waits to get the oil change. My local dealer picks up the car if you had purchased it from them with a flatbed, performs all of the annual service and then returns the vehicle. Annual service is 1K alternating with 2K so total in the coverage of the 458 is 10K.