I actually don't want to comment on what happened to the clubs that played pre-season matches, including Juventus. Because what we saw in this match can't be used as a conclusion that their game will be like that when the season starts. In fact, one of the reasons why I don't want to bet on pre-season matches is because they are not serious about winning.
I think we have heard many coaches say that they are not focused on winning in matches like this, they say more that they only focus on their form of play, while seeing which strategy will be their mainstay. Usually they play all the players they have, and in strategy they try many strategies that are aimed at refining the strategy that they will use in the league. If their orientation is only on winning, then I don't think it can be called a trial match.
Yeah you are right, and matches like this always happen every year so no need to be surprised. Winning is not a priority and almost all clubs have new players so they need to play them as a trial to determine their positions and build chemistry that's why we saw Juventus make 11 substitutions, also to determine who deserves a starting position in the new season. Juventus still have 2 friendlies match ahead against Brest and Atletico Madrid well we don't need to seriously wait for this match because there is a possibility that a similar defeat will happen again and as you said we have reasons to avoid betting on matches like this.