I have often argued for a move to the 3sensor array as traditionally found on tv cameras.
This means a true colour value at every pixel, but it also would mean 3x the sensor cost, and the cost of a very large dichroic prism and assembly.
It would also make for a larger camera.
When you have mote than one sensor you can employ 'pixel shift' where the green sensir is offset by half a pixel, with massive gains in apparent resolution.
There is some precedent, Minolta had a multi sensor camera in the very early days (the rd-175, although the sensor wasn't split straight rgb) though very costly and more the size of a mf body.
As the Tv world has been quick to embrace single large sensor cameras with bayers, maybe the stills world could steal a trick from the tv camera world (sony and panasonic already manufacture 3ccd and 3cmos arrays)
I doubt any such camera would be intended for anything other than very high end professional or industrisl use, but like f1 cars, the lessons learned at the sharp end make better products for the consumer, over time.