I would be very hesitant to send him to the Vuelta. Just rest up properly, and maybe do some other races to invest in the next year but no Grand Tours.
Agree, that's the smart move, but I imagine they're under some real pressure to produce something this season. In hindsight - and to be fair, this was less clear at the time - they have made a mess of the season:
Tour - put all their eggs in a basket with structural weaknesses (Bernal)
Giro - removed the defending champ who had built his season around defending his title from the race and wasted him in the Tour; instead sent GT who, in all fairness, should have a decent result, but who is a) not the defending Giro champ and b) a better domestique due to his ability to crank out steady watts and extensive experience
Vuelta - so far only announced Froome, as far as I know, who will produce no results, through no fault of anyone's; it just is what it is post-crash
So as it stands, their only legitimate hope is that a 35-year-old who was a domestique until 33 and just struggled hard in the Dauphine pulls out a victory in the Giro...
I actually think GT has very good odds of finishing on that podium, but still, I'm sure Brailsford will try to do something different with Bernal or Sivakov or Carapaz to try to get something...