No idea, but right now I'd give him the benefit of the doubt. He was clearly a spectacular talent early, like LeMond or Fignon, not like Armstrong or Riis. Also, the 5+ gap to second is misleading: more than half of that came when JV was still trying to get Roglic back in the race. The race overall was a bit strange: Omi-Opi took out some serious contenders (who would not have beaten Pogacar, IMO, but we'll never know) and other pre-race favorites were beaten not just by Pogacar but by another young unknown Vingegaard. And his wins in the mountains were in his element -- cold weather. How he'll do in the high mountains when its hot remains to be seen.
But it's sad that we even have to ask this question. Part of me does wonder. Just as I wonder about van Aert on the Ventoux, or for that matter MVdP at Strade Bianche.