Pg. 411:
After the GM has chosen his Infection maneuver and written down his choice, the players discuss their options openly at the table. Once a decision is made, the GM notes the players’ choice and we dive right into play.
So the GM plays through the maneuver knowing what the players have chosen, but the players don’t know what the GM has chosen – correct? Why, exactly?
Correct.
What does your gut tell you? I’m not being flip. I want to know what your interpretation of the rule is.
I think it creates a bit of mystery for the players. It “feels” (a little!) more like a traditional RPG if the players don’t know ALL the cards the GM is holding. It lets you be kind of, you know, sly about what you’re doing with your turn. There are precious few “big reveals” as it is.
The secrecy probably only really matters while the players are picking their maneuver. It’s important for the GM to listen in on the players’ thoughts and ideas, so you can’t do a simultaneous reveal.
p.
Well, in my group, I’m definitely going to be the person who knows the rules best, so as GM, I have to listen in on the players’ deliberations and advise them, at least at first, for them to have a fair shot so the competitive side of the game can work. (Like a more experienced tennis player running the novice hard as he can but still yelling advice: “No, no, come up to the net more – c’mon – you gotta get aggressive – yeah, that’s it!”). That part makes total sense to me.
Paul’s old-school GMing reason makes some sense to me. It also makes some sense that the GM is outnumbered by the players and needs a little edge of superior information.
But honestly, as I think about it, the explanation that makes the most sense for the asymmetry in knowledge is the asymmetry in roles: The GM’s not another player, he’s in many ways less than a player, and his characters are less than full protagonists. The GM and his characters exist only to apply pressure to the players’ characters, to give the protagonists the force to work against so they can develop their full strength as heroes. But the players and their characters aren’t there to develop the GM’s characters. So the GM, to do his job, has to know as much as possible about what the players want their characters to do, so he can apply pressure at the right points; the players simply don’t need to know what the GM’s up to in the same way, because it’s not their job to pressure his characters into growth the same way.
I also think it keeps a bit of tension (not mystery, but that’s been brought up and is a good point) in the macro-scale game. The players don’t KNOW if the GM picked the perfect counter to their maneuver, or if they’re gonna mop up in the Infection. It helps focus the scenes towards the Infection if the players have to bank their scenes for Artha to use on a maneuver that might not be a sure thing… so you better have that Artha! I explained that poorly… hrm.
The players don’t know if they’re gonna skate by, get hammered, or what. They need to play hard to get Artha to save for the Infection roll because they are being forced to plan for any contingency. I guess. 
Paul, Sydney, Adam: a combined yes.
And I also agree with Syd and Adam. Good points, guys. We rock! \o/
p.
Also keep in mind that uncertainty breeds begets uncertainty. Just going off general life observations, but because the players don’t know everything tends to become less certain from the GMs perspective what they are going to do.
It is like a vetern of a game going up against a noob. The noob doesn’t know what they are suppose to do in a given situation so their actions become much more unpredictable.
THe analysis isn’t really complete though, since only half of the leftover disposition carries over into the next phase. Disposition in the invasion phase is far more valuable than disposition in the Infiltration or Usurpation phases.