Spare parts, be it a car, truck or bike... it's either on stock or not....
Defective starters are not common, so most probably, the dealer don't keep them in stock and order only when needed. Also, most probably, you're starter is shipped together with other parts the dealer ordered from the source. Maybe you can have it prioritized and have it flown via air, but you have to pay. Shipments via sea takes months. Almost a month is a short time....