I don't understand why there has to even be a reason. I mean everyone knows what the Cubs are doing. Something about good faith in employment laws or something. It's deeper than the CBA itself. But the labor laws were collectively bargained? How can the PA argue that the Cubs are doing wrong when they agreed to these rules? I understand everyone thinks it's [expletive] but so is paying some players way under market value their first 5 years in the league. Because that's just how it works? I dunno, IANAlaborlawyer. It's probably different in every state and every level, and it's probably never been tested so there's no real precedent here, but there are examples where common law "don't be a dickwad to your employees" principles can outweigh a contract or CBA. All sides are acting like it's at least theoretically possible for the team to lose if it were to go to an arbitrator and they made it obvious enough.