I was just talking to Tomm Hulett, the producer of Contra 4, about this soundtrack release.
It is only going to be available with preorders of the game; it will not be available separate on Konamistyle. So likely, Kahori will not have it (I hope I am wrong, but it's not looking that way).
The only way to get it is to preorder the game somewhere. Tomm told me he is doing that himself, so if the producer of the game has to preorder his own copy, well...
He also told me something about the tracklisting that is sure to please, but he made me promise that I couldn't tell.