I don't understand why shipping rates would increase because Apple has taken capacity away from DSL. Why wouldn't DSL charter/lease special planes just for Apple's shipments if they don't have enough available? When FedEx or UPS has increased demand around the holidays they don't raise their rates because they need more capacity, they just pull additional planes out of the hangars and blow the dust off or increase flight frequency. It's the nature of the shipping beast, so to speak.
You can't just "charter" or "lease" capacity without incurring rising costs to your own price. Overtime, employee's, rentals, etc. all make brief moments in time like these more expensive. If it didn't work this way, everyone would own a freight company. Companies have to get freight capacity from smaller outfits and they may or may not charge more. My guess is they are not as efficient as UPS and FedEx.
The article is just stating since Apple has taken a large chunk of capacity the price of shipping in general has risen in the near term. Prices will stabilize or UPS, FedEx, DHL, and others will expand thus decreasing the price sooner or later.