There is a difference between death and disappearing? Interesting. That had him pondering things for a bit longer. Made him think of what Deepground had done, what the Turks regularly did back in the day. And, of course, about the stigma of magic users when Shinra had been in power.

"These people who disappear, it is assumed they have not just died somewhere in the wilds?"

Because yes, this is information and he cannot live without that. Information is required to make appropriate plans for the future. Including ensuring there is a way to prevent the latter if that was what was really going on.