Without knowing the details, it seems that we have a "conceptual shift" here in this camera.
First, it was goind to be a camera body made by F&H, then modified for each back, and sold under the name of each back maker. Leaf and Sinar liked that idea, and put their name on it. Attractive proposition at first.
Of course, with more reflection, they all probably realized that while that gave the back makers the assurance of having a camera body to take their back (good, as this is a source of concern, esp. if Hassy goes closed), it also put them peculiarly in the camera business. For example, do they warrant the bodies? Preferably no, but in this scenario, they would have their names on the front of the body.
So I suspect they are all moving toward having Rollei/F&H or Sinar putting their name on the front, and making a more universal, open adapter system on the back side of this camera body. This way, the back people stay in the back business, and the camera body people stay in theirs.
Of course, this leaves F&H in the awkward position of making a body and not sure about whose backs will be there. Assuming the backs show up (and they probably will), who handles distribution? If Sinar takes it on, they'll prefer to have their backs mounted with it (ala Hassy). F&H would prefer the largest success possible for the camera, and thus want the most open system.
If Sinar is generous (clever?) they'll keep it open as possible, but given their currrent pricing approaches, its not too likely that there will be "deals" with the other backs that undercut their own back/camera approach.
What we have here is a series of differing agendas, working themselves out in front of our eyes. They and we all want a system which will take differing backs. How we get there is a bit awkward.
Making a new body working with differing backs is difficult enough, but doable. The distribution side of this is where the wrinkle is - any back maker who distributes this kind of camera will have a bias toward their backs. If the distribution side looks more like Alpa (who don't have a bias to whose back or lens you put on their camera as long as it works), then we would all benefit.