The site speaks about the FPU in these terms (underlined of mine):
After 18 months of intense research and development, Impossible introduces a groundbreaking module for analog instant photography: A high precision platform named "Impossible FPU" (Film Processing Unit), that processes and develops Impossible instant film. This highly advanced device is the basis for a range of new analog instant cameras and hardware concepts to be introduced in 2013.
This indicates, in my view, that the project focussed since the beginning on the development and launch of the FPU platform which is to be "declinated" in several products. The basic module being the same or almost the same, it makes sense to launch the other devices as soon as industrially possible. Who knows, one day the FPU could be used to make a back for MF cameras! (That doesn't look very likely to me, but if the module is, in itself, "almost" a film back then why not).
Standardising production of several products around a common module is, I think, a very clever move. Film quality and film cost remain the biggest hurdles IMO.