very true, its a fine line to tread and he needs a good set of people around him to tell him when the moment is right and when it isnt, which Im sure he'll have.
but I can assure you when youve worked as hard and sacrificed as much to get to this position for this season where he had big goals, to have that all taken away by a crash like that, which he no doubts blames himself for as well, he'll be endlessly replaying that moment and berating himself for why didnt he do something different, and with the amount of injuries, I mean a collarbone would be one thing but we know most riders bounce back pretty soon from that, but with the ribs and the sternum too, and then to say well thats seasons done, dont aim for anything this year.
he will find himself suffering from depression, the what could of been, the blame he puts on himself, will he get that chance again and so on and that can be even harder to overcome and recover from than the pure physical injuries alone without something to aim for.
something to target as a ok we're in a bad place at the moment, but if we focus and look forward, instead of back or at what might have been, at where we want to be next, it can be very self defeating, why train hard at all if all that happens is you get injured again, why bother ?
IMO elite sport is much more about mentality and mental strengthness, rather than the pure physicality, and he needs to target a race this season to aim for, he might not be ready in time for it and then has to pick a new goal, but without that kind of impetus behind his recovery, it will be much longer and more protracted, and he might not end up as good a rider as he was before.