Even if the UCI does approve disc brakes for sanctioned road race use. I expect the teams will be slow or never adapt them. The problem is they slow down wheel changes appreciably as you have to carefully align the rotor with the caliper as you install the wheels rather than just jamming it in there as with side pulls. In races, where a slow wheel change after a flat can make it impossible for the rider to rejoin the peloton, that could be a big consideration. Perhaps it can be designed around but not with the current disc format.