That is of course true. But unless I am mistaken the removal of CFA brings up the broadband signal about 1.6x compared to the colour sensor. So in terms of QE we have:
real mono sensor = 1
debayered sensor = 0.6x
colour sensor = 0.4x
If I am right the debayered sensor sits in between the other two in terms of QE. If they can do the debayering well this may be the market for the new camera, depending on the pricing