It's not a bad basis for the prediction. It is after all a similar kind of effect to the Kinectless Xb one announcement, which made May NPD into a complete write off for Xb one.
But I don't Destiny will have that big of an influence on the pattern of PS4 sales. Lots of people, right from when Destiny was first announced had probably decided to get PS4 only when Destiny comes out. So they were committed to a September buy anyway. Anyone not planning to get Destiny, but planning to get PS4 will maintain the PS4 buying pattern. Destiny will be big. But it won't be so big as to noticeably suck the oxygen out of hardware sales leading up to it.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix
