But whenever they reboot a us vpn server somehow that password is making it into the LUKS system (can we assume some kind of agent that runs during boot?) which

But whenever they reboot a us vpn server somehow that password is making it into the LUKS system (can we assume some kind of agent that runs during boot?) which likely has some credentials also baked in? Unless we believe a human being is manually entering these in their hundreds of us vpn servers every time they restart?