Smart marketing. It will appeal to roadies with OCD (ie, Every Single One) who want to make sure the tire they get is optimized for aero with the Enve wheels. I have to admit, a similar reasoning was the tie-breaker decision in me choosing to get the CLX64 for my Venge - figured with all else being equal, i might as well get the combo which Spesh most likely used to optimize their bike.
(I wrote that while the announcement page was loading on another window and yup. "Designed to deliver maximum rolling efficiency while eliminating tradeoffs". If you are buying $2500 wheels, why not pay a little extra and get tires that are likely best suited to your tires? Lot of people will buy them for that reason. Hell, if i ever get Enves, i will probably give them a go as well)