Vingegaard doesn't always attack early, and especially not when he's up against Pogačar in the Tour. And unlike this year, I don't expect there to be the same kind of uncertanty regarding Pogačar at the start of next years TdF, which makes it less like that Vingegaard will risk anything in the first part of the race.
We saw an interesting trend at this Tour. Even since Pogacar's successful counter-attack in Cauterets Vingo was very anxious when Pog was on his wheel. No more Mr Confident that we saw on Tourmalet and Cauterets climbs. They only managed to gap the rest when they rode alone (Joux Plane is a perfect example when they stopped when Vingo caught Pog, another example was Vosges stage). Actually it seemed they didn't want to cooperate at all. In case both are similarly strong next year (and neither can drop the other) they could have problems with distancing the rest