You can chat all you want with your friends over coffee about stealing stuff and although it's psychologically messed up, there's nothing legally wrong about that. It's when you actually steal that you've committed a crime. Same thing.
Taking the tech wage collusion example, the wages themselves were still very high (we're talking about Google and Apple salaries here) but the collusion to keep them from being higher was still a crime.
Tech CEOs can talk about whatever they want. The talking isn't the crime it's the act. They could talk in theory about colluding, it becomes illegal when they DO it. I'm not sure how else to explain it.
You can chat all you want with your friends over coffee about stealing stuff and although it's psychologically messed up, there's nothing legally wrong about that. It's when you actually steal that you've committed a crime. Same thing.