Just to make it clear if it was said or not. The Jutsu Naruto is trying to master is not a Wind Version of Chidori. As it was stated, Chidori is only a technique that has brought out the Maximum Nature Manipulation of the Lightning Element. Rasengan of course was also stated that it is a Natureless move that only involves the Form Manipulation of the Users Chakra, Yes it is very well that Sasuke can learn it. Though could it incorporate it with his Lightning Element or his Fire Element. Probrably not. If he could it would take him a hell of alot longer then Naruto since Narutos Tayju Kage Bunshins at 1000 allows him for last Learning. In a sense so everybody knows if they don't already. The Technique he is making is not a Wind version of Chidori. What it bassically is doing is adding his Wind Version of Chidori, which was when he cut the waterfall in half. Adding that to Rasengan.
So all you have to think of it ass is Wind "Chidori" + Rasengan = This new jutsu.
Not "Wind" Chidori all on its own.
