The promotion of Zeiss RF cameras manufactured in concert with Cosina may even be left at the local national/regional level. There is a long-time Cosina-Voigtlander vendor in the US who at first had the ZI bodies and lenses, and lots of information on them on his pages. But for some reason, his official vendor status was pulled and Zeiss awarded "franchises" to other vendors. I don't know where this action originated, but I'd be very surprised if it came from Cosina, because of a close personal relationship between this vendor and the owner of Cosina.
Most likely it's Zeiss trying to differentiate itself from Cosina. There are other vendors who carry both these lines of rangefinders in the US, but they carry many other brands as well. The vendor who had his supply of ZI gear cut, cameraquest.com, is pretty much a Cosina specialist.