What's the point? They would fit in if there were unfilled roles in the setting (just actions and characteristics), but it already has names and descriptions, which makes the character sheets useless – a typical link to a wiki would serve the same purpose, and wouldn't require players to spend time. And if (suddenly) they were used in newspaper descriptions, then it's unclear why pre-made characters are needed.

1. For atmosphere.
2. So that the player can choose the information on which clues will be given, without a mountain of unnecessary text on wiki pages and without it overlapping with other players.
3. For role-playing during daytime discussions. You won't role-play the role itself; they'll immediately slap a "metagaming" label on you.

But this is not so important in principle. It takes a maximum of 5 minutes to come up with a character; I didn't initially think that such problems would arise.