Juventus' victory in the first match is certainly extraordinary. Despite winning 0-3 over Udinese, Juventus' performance was still unstable, this can be seen in the first half they got team luck from chemistry but in the second half it was very concerning. In my opinion, I doubt that if Juventus were still coached by Allegri, the games would be like this and there would be no progress. The attack scheme is never clear, the goal process is not far from penalties and scrimit that is not intentional, every time the superior defends immediately. Won't win in Europe if the coach is still him.
A good start to the season for Juventus because I can get full points over Udinese, I agree with what you say. Juventus played well in the first half but in the second half Juventus looked to have underestimated Udinese as they were three goals ahead and Udinese dominated most of the second half. I hope Juventus don't do something like this in the next game, especially against a strong team because for me it would be a mistake to slow down when they are already ahead.
But whatever it is, Juventus have had the upper hand this season, smartly risking everything for Serie A and deciding not to play in European competitions. I think this is a good strategy to focus more on winning the Scudetto trophy. At least Juventus this season can return the local championship title before returning to play in European league competitions in the future.
Juventus this season are not playing in Europe, maybe at this time they can focus 100% on the Serie A League. Of course, this is a distinct advantage for Juventus because Juventus' concentration is not divided. If Chiesa, Vlahovic and Rabiot keep this momentum going, Juventus will be a huge force this year. As long as they don't drop points against the so called smaller teams of course!