What evidence is there of that? If anything, I would support the idea that demand is typically lower on the S Cycle, since it isn't attracting as many people seeking the iPhone for it's new looks (unlike the Non S cycle).
I am not talking about demand, demand might be lower but supply should be higher on the S cycle and since demand is generally higher than supply regardless of the cycle they should be able to sell more of the S model in the first week sales numbers that they tout.