I am not aware of such a setting, but I can see the benefit. You might check Facebook and see if the suggestions page is still available. There was word that this was going to change, but I have not seen the new method being announced.
Most systems continue to announce so as to ensure that all know who is connected and listening. Otherwise, there would be nothing to stop someone who is not to be a part of the conference from becoming an unknown and unwanted participant should they know what the conference # and PIN (if applicable) are. On the other hand by confirming those who attended, it may eliminate the possibility of those who might otherwise indicate that they participated.... but didn't.
Nevertheless, I see where late arrivals could hinder the meeting progress by the interruptions.