The article uses "text" and "call" and "contact" as if they're indistinguishable - what actually got banned here? There's a huge difference between discussing a task for someone in a team channel and @-ing them and emailing them and SMSing them.
Another reason why it won't mean much is that the employee is the one that needs to make a complain with the work authority, and then work authority has to evaluate the case and decide it they will issue a fine or not.
So what this really means is that if my boss contacts me after work hours I can (and should) ignore him without any repercussions.