There's almost always no shows and misconnects. Don't forget about people potentially buying LMU's. If AC's revenue management has any brains on a flight like this they'll actually make an LMU at an attractive price as well so that people are enticed to take them.
Also, no one will ever call you in the AC lounge. Most airlines (at least that I've flown) specifically say "no announcements are made in this lounge", that refers to not only flight boarding but also personal announcements.