A broken scapula and clavicle 2,5 months before the Tour never helps to perform at the highest level in that Tour. But..... turn it around. It happens way too often that riders unhindered by illness, injuries, (long) inactivity, having a perfect preparation (or think they have), having a (almost) perfect weight, overdo. Being in shape too early, having drawn too much in the reserves for the Tour...... start strong the first days of the Tour and fade later..... or not even perform the first stages of the Tour. As we could see about several riders being in (top)shape during the Dauphiné. Already during the first (hilly) stage of the Tour, some good (subtop)riders lost time (while not climbers and even alround sprinters were still at the front). On the San Luca, the likes of Roglic, Vlasov, Rodriguez, Jorgenson etc were already dropped. While the "bad" prepared, crashdiet Evenepoel lost only seconds and even came back at the end.
So, without that nasty crash, Evenepoel would have been better prepared. But I'm not sure that would have resulted in a better endresult, or even the same result. It would have in the case of Vingegaard. While Vingegaard really couldn't start his specific training in time. Unlike Evenepoel who gets into (top) shape just in time.