I think the cool aspect of this rumor is that it mirrors the X series development. I think the X100 was an experimental proof of concept. The fixed focal length, OVF/EVF rangefinder esque camera. People loved it and it launched the X series.
Fuji has an awesome history of producing fixed focal length RF medium format camera. They have the know how to produce a OVF/EVF camera bar none, and they could test the medium format waters by producing a fixed focal length MF OVF/EVF camera.
If people bite, maybe you invest in developing an interchangeable lens system.
I think its an exciting rumor. They have the experience to pull this off, and a carry round MF camera with a leaf shutter would be beyond cool.