I came across this today when I was sitting in school and playing around with cards. I don't know if this "sleight" is already known under someones name, if so, sorry about that and correct me pls =)
Let's come to this move. After you did the snap change, you can palm the vanished card in a kind of a tenkai palm. not exactly a tenkai, but good enough to spread your fingers out again (nice convincer) put your fingers on top of the card, put he card on the palmed card while putting both back onto the deck. while spreading the fingers you should get a small change of the angle, just like tenkai.

just came in my mind, feedback would be nice

A noble effort, but I've been doing this for about a year. And it was taught to me by a 30 year veteran of magic. But you get points for devotion and cleverness!

I do agree with you that this is a killer little move and was completely smitten with it when it was taught to me.