As mentioned above, most cross bikes are sold to non racers so the market must be pretty large though I still think the development will be (pro) racer led.
I don’t agree with the old adage that you don’t need good brakes for cross, especially with all the dead turns and such on modern courses, I see plenty of overtakes by out-braking. In the dry cantis can be set up well enough to be sufficient and keep weight down but in the wet discs would really come into their own, especially with carbon rims. I would be very surprised if we don’t see some pros on proto disc set-ups for a few races this year. Di2 hydros would be ace but perhaps that market is too small?