Second, this line, right from the article, answers it all... "The case is under seal because it involves minors." Many State's have laws which prohibit releasing any information about a case involving a juvenile. It's only been in the last couple of years in my state that there has been a change, and public records laws now apply to juvenile cases. Still, probation officers, court employees, and staff are prohibited from discussing court details with anyone outside of the parties to the case or court staff.
That was my thought. "It involves minors as perps, which means they get the same extra privacy protections that minor victims do"
I remember reading about a case that involved a minor female and child porn. Produced, scripted, recorded, edited, and distributed by her. Yes, things would have been a whole lot simpler if there had been an adult involved to place the blame on. Yes, they wanted to find that she'd been sexually abused by somebody - so they could transfer the blame to them for the 'bad behavior caused by mental trauma...' Nope, none of that.
As I understand it, the Judge slammed down gag orders that would make the controls on TS:SCI look like FOUO. I like to joke that he ordered the windows boarded over and snipers posted to keep the media away.