the only strong argument for radios is safety. the riders claim that dangerous or changing conditions up the road can be relayed back to a charging peloton. a weak reason in my opinion but mostly solid logic. (i could make the argument that an entire peloton with distracting radios in there ears are a bigger danger but whatever)
solution:
radio contact from race organizers to riders alerting them to unsafe conditions if they even exist. in other words, riders can listen to "race radio". may need a couple frequencies for different languages but very cheap technology in this day and age. problem solved. no radio from rider to DS necessary.