What's the purpose of the fire alarm

I think part of the musical chair problem is that the game picks where a sim should do something at the time the action is queued and then re-assesses periodically, but it never seems to re-assess the initial queued location for future actions. So if your sim, say, queues up "tell a joke" while standing, then finds an available seat they will stand up to tell the joke again then discover they can, again, sit because there is now a vacant seat... that they were just in.