This general idea was suggested almost a year ago, but nothing's happened with it. If you want to give them a little reminder of this idea, then you should probably put this in the Customer Service/bugs and support section.

I've come up with a few ideas regarding possible Stage 2 form abilities in the "Fanmade future ninja talentsets" thread in the Plot section as well.

I did try to make a "Kin Shippuden" at one point, but it's probably buried in the fanmade talentset thread somewhere.

Well, Kin's actually my least favorite of the Sound Genin, mainly due to her lack of characterization compared to the other two (while I didn't find anything particularly bad about her. It's just that I found Dosu a much more interesting character and Zaku had an actual backstory, albeit somewhat small). However, she is still a Sound Genin, and I support all notions of adding more of the Sound Genin into this game :D