I don't see why.
Indeed, it will presumably work just fine in Raw, although the functionality may require a special Raw conversion plugin/application if it is not done in camera (a plugin like Olympus did until ACR implemented it natively). If it is done in-camera, then the Raw file would be larger because it now has to store RGB per pixel instead of 4x one color plane per pixel, and a Raw converter would have to understand that no demosaicing needs to take place.
The interesting question is whether this tech will be in future Pentax MF bodies. Could give the Phase 100MP back a run for its money ... at 20% of the price.
I think it's unlikely to become mainstream, or available in all Pentax bodies. It's a specialized capture mode for stationary subjects under stable lighting conditions, so more suited for professional/studio work. Ricoh/Pentax have only implemented full sensel shift, so we only get an improved RGB colorsampling, no super-resoution enhancement like from half-sensel shift multi-shots.
Your continued stabs at Phase One get a bit tiresome, but a camera and support system is more than a sensor at a low price. Besides, the Phase One system uses a 16-bit processing pipe-line which achieves something like more than 14.3 stops of engineering Dynamic Range at base ISO. That is unlikely to be achievable with the Pentax if they use less than internal 16-bit processing.
But the Pentax looks like a nice camera with interesting features. It will depend on the lens arsenal whether it gets major traction in the market, and how well their service organization is implemented if they want professionals to use the system.
Cheers,
Bart