Well, the simple answer to this question is: no, Juventus did not violate health protocols.
But let's recap what happened: this morning a few websites and newspapers titled their articles regarding Juventus players selected for national team football "Juventus players violated health protocols by leaving self-isolation". Is that correct? Well, not really. At least, that is not the full story and it is not how things really went down.
So what exactly happened?
After the last round of matches, national football is back. Therefore some Juventus players have been selected by their respective national teams.
Juventus, as you all know, is in self-isolation after a couple of external staff members have been tested positive for COVID-19. What does that mean? By Serie A protocol: they have to self-isolate in a venue previously decided and declared to the Lega Calcio. In the case of Juventus, the team picked the J|Hotel as its isolation venue.
But what happens if a player has been selected to play for a national team?
Well, first of all, another protocol comes into play (in this case I believe it's the FIGC protocol, although I'm not 100% sure) but certainly the Serie A protocol is not valid once we are talking about another competition, of course.
The protocol procedure says that Juventus has to notify to the local health authorities (ASL) the players that are leaving the self-isolation in order to reach the national teams.
ASL, upon notification, sends the information to the federations involved and applies their protocol.
Why? Because once a player is selected by a national team it becomes the player's and the federation's responsibility.
E.G.: Chiellini and Bonucci did not reach Coverciano before yesterday. The only reason is that the FIGC protocol says that ASL needs to test a player who is in self-isolation after. ASL tested the players, both negative, both reached Coverciano.
Why did the ASL notify the authorities of "breaching the self-isolation"? Because technically they did breach self-isolation. But of course, the authorities will take note of that and the fact that they did so in order to reach their respective national teams. Ergo, it's a non-news, it's just protocol.
Now, is the team liable? Not at all. The team CAN NOT force players to stay in self-isolation. They can only notify their local health authority and then the ball is passed to the Federation that becomes liable, together with the individual behaviour of the players involved.