That was just an example, you must agree that we can't do much with this til roles are claimed, while mafia can do 2 things:
- Make sure they don't accidentally fake-claim a role they had before, as they have a neat list.
- Can choose killing targets based on who is likely to be Detective, Doctor or whatever they're gunning for. Think already several people are out in terms of possibility of being Det/Doc.
Not that they can't find the players' past roles themselves(pretty sure we did that when we were mafia last game Demon) but it certainly helps them save time.