Rashi is saying that the passing of tzaddikim atones for the people. As in every time. I have no idea why you would walk that back.
We have the free time to put things in perspective. But the families (as well as the survivors) may be overloaded between their internal sense of loss and the public portrayal of the larger tragedy. Comfort is found in accepting what happened. Adding on possibilities that a tragic, early death has cosmic implications, avoids what the life of the departed was like – and even more – could have been. It moves the focus of the personal greatness of each individual life to the overall placid and non descript merits-versus-sins of the masses.