Actual reason: because there are different firms administering these settlements. You want to separate these by subdomain so that there isn't a chance that an administrator from one site hijacking into another. Unless you're proposing the government to directly call/mail affected persons (might be desirable in cases like the JnJ Talc powder case where it is clearly a retail case).

Ah that's a great reason, thanks. It helps when you framed it up in current events, really made sense.