It would be hard to imagine the longer term contract rider, Carapaz being OK with the 2nd seat to a guy headed out the door. Ineos could have a revolt on their hands if they played that angle to the riders and Froome didn't win and Carapaz was compromised. They'd be right to be pi*sed.Froome is not the kind of rider who enters a GT just to get some miles in his legs. Realistic or not, he's thinking contending and winning. From that point of view, his order of preference presumably would be:
TDF - wants to win no. 5
Giro - a win would give him 2 or more of every GT, joining Hinault and Contador
Vuelta - doesn't need another one, but it adds to his GT wins, takes him past Indurain and Contador
There's only about two weeks between the end of the Tour and the beginning of the Giro, but if he only rides as a dom in the Tour, is allowed to rest on a lot of stages, he could show up for the Giro in pretty good shape. OTOH, I guess Ineos has promised Carapaz leadership role there (?), so unless Froome showed real strength at the Tour, I assume they wouldn't let him ride as leader or co-leader at the Giro. The Vuelta, starting a few weeks later, would also give him more time to get in shape, and after that accident, can't be too much time to recover. The Vuelta is also a crapshoot, as who will be there will depend somewhat on what happens in the Tour. Any TDF favorite who disappoints there will probably want to salvage his season in the Vuelta.
I do agree the Vuelta will be the season's GT cage match for all comers.