The only person we've seen with the ability to put that data together is Tarquin, who characteristically does not tell you what he knows. Maybe Malack is in a position to notice lots of deaths, but a cleric of a god of Death will be less horrified than others about it.

Beyond that we've seen the Order of the Stick, who arrived after it happened, gladiators locked away from the world, the Linear Guild who is focused on their own quest, an elven ambassador whose city was under attack, and bounty hunters who just got here. Who have we actually seen who could have noticed it?