I doubt that, because Apple's well-known penchant for extreme secrecy would tend to preclude the store's having foreknowledge of the Air's demise.
Assuming the decision originated at the local store. It could have been handed down from or recommended by Cupertino.
It doesn't look like a Kensington lock slot requires all that much space, but the way Apple has been designing things lately, a pinhead might take up more space than there is.
I have seen photographs reported to be MacBook/MacBook Air prototypes where the hinge is a flexure in the case to save the space required for a hinge pin.
It seems like the more compact Macs get the more we either give up in the process or the more cumbersome compensating for it gets.
Even though computer sales represent a decreasing shore of Apple's business, those sales continue to increase while computer sales in general continue to fall. As long as the market continues to demand slimmer, lighter, more powerful laptops with 12 to 15" Retina displays and longer battery life Apple will continue to meet that demand even if it means there isn't room for non-essential (albeit nice-to have) features such as headphone jacks; USB 3, Firewire, and Thunderbolt ports; upgradeable memory, and Kensington locks must go by the board.
