Maybe apple just has too many in stock to bring the new ones in....
Either way, I still se many people buying the d2c's without any idea of the possible refresh, which makes apple say "we are still selling the old technology at this price, well just bring in the new ones when sales go down".
I bet they've had the new refreshed MBP's ready to sell but they don't see a reason since there are still buyers paying top dollar for this stuff