Mostly just because I feel it in my bones, and go almost entirely by vibes in the early game.
Buttt..... if I had to say something more concrete, I'd point out that you seem to be giving them towny points for initating setup spec discussion, which IMO is NAI. However, they gave themselves an out to base their D1 reads just on how people reply to setup spec, and IMO that is a red flag since again setup spec is NAI (easy for wolves to do, especially since many people do setup spec before they get their rolecards), and it leaves them the ability to pick and choose who gave "good thoughts" and "bad thoughts" without really having to explain why those people are suspicious.
But now, they seem to propose a strategy... but they are completely missing the actual value of that strategy, so for someone who wants to talk setup, I don't feel like they've actually considered how different strategies could benefit town (in particular, they seem to think the strategy's benefit would be to generate chatter rather than y'know... clear people).
Finally, the first post is one of the most vulnerable as wolves. As town, there is no pressure so it is easy to make a first post, but as a wolf, the pressure is greatest then (and after the first post, it is easier for wolves to get into the swing of things), so wolves tend to make certain types of first posts, and this sort of "vaguely helpful while asking a question" type first post is >rand!wolf IMO.