Hm, that's odd. Certainly it all pointed to it being a Koto piece, since they even showed it with their own sign and posters:
But yeah, you can't find it on any of the Koto sites (Japan, US, Europe).
I guess this also rules out the similarly styled WW vs Cheetah piece:
Perhaps Koto US had decided to distribute these pieces on their own but Kotobukiya shot that down?