You can't just take one example (as here Küng) and then pull conclusions. Moreover, his result in the Giro was also an outlier. For instance in Tirreno last year (13.9 km) he finished second after Ganna, 13 seconds ahead of Asgreen. Now he's 17 seconds ahead of Asgreen. Off course he doesn't have the form of the opening TT of the Giro. I doubt he will have 5 more days like that, where he annihilated and obliterated the whole field. But given the current circumstances, this is a very good result. We have to see what happens next, but again, if I were Van Aert, coming from an endless training camp and coming third here, I would worry a lot more.
Edit: That doesn't mean I think he should be going to the Tour by the way.