Conflations aside, your source is not saying what you want it to pay. The tzaddik atones for the people on his/her passing. Much like they do when they are alive. In such an instance we would say the departed was a tzaddik, not a korbon.
It does not refer to the untimely passing of the young. Or the bewildering tragedy that just occurred. Using these term’s comes across as flippant, and does speak to the sub conscious realities.