I hope JV take good care of Primoz, and pay attention to this back injury. If he really has (had) two broken vertebrae, then this needs time to heal.
This are serious injuries, and the crash has happened just few weeks ago. I don‘t know if riding a 3.5 week long bike race through all of Spain, with 3 500 kms and 50 000 vertical meters, ridden with 42 kms/hr average, is the best thing to do in this situation. They certainly will do X-rays frequently, and see how it heals.
If it hasn‘t healed 100%, he - IMHO - shouldn‘t ride the Vuelta. Going into a GT with the goal of hunting stages or even GC would be crazy, with a still broken back.
Why not let it heal properly, then focusing on next year‘s Giro? Then, after Giro, no races at all, and start the TdF without pressure, just to see how it goes. Sounds good, IMHO.