It is very typical for them not to inform the employees. Whenever I ask an Apple engineer about anything legal or a lawsuit it is usually news to them. When I worked for a previous company there was a lawsuit going on by someone that I worked with and they kept everything and everyone in the dark. I think it is just how they deal with things. You don't want to cause a huge panic to your employees a lot of them may jump ship at the first words of class action lawsuit.