It's honestly stuff like this that makes me feel like the only sane person around. Why would you do this? If the CEO is pushing for it, the employees will all smile and nod and go along with the crowd, but all this does is breed resentment. The idea of open salaries sounds good on paper, but it's simply idealistic.
You can sing the happiness song and do all the lets-be-friends dances but at the end of the day we're people competing for resources. This will have lasting effects to all current employees for sure.