UCI rule 2.3.027 No supplies may be provided on hill climbs or descents or during the first 50 and final 20 km. I did see hand ups today inside the last 20K, but with 100 degree heat over the roads, perhaps LeBlanc said OK.
You can only carry so much in the team car anyways, If the Riders are drinking an average of 15 or so bottles a stage, thats 135 bottles, plus food.
It also cuts down on the number of times the domestiques have to go back to the car, who wants to fetch enough food for 9 guys over 7 hours. Especially if your team car is 20 cars back.