Stastics and manipulation of the lobby are two different things. It's all in the player's hands to dictacte if they win or lose, with of course the random factor and the chance they're found -- which can be played in many scenarios that also sees town losing, as well -- so in the end, to try and argue "so and so role has such a low chance of victory against this and that" is pure speculation and opinion, since no one can honestly say how each and every game will play out since it's controlled and played out by humans, which in of its self creates an unpredictable scenario 100% of the time, even if you played the same setup 100 times in a row. So to try and use that as your grounds for argumentation, is irrelevant and automatically shows signs of a poor decision to hold grounds to argue when you're trying to add an ability to a town role that is not meant to yield deciesvie and problem-solving messages in the scheme of settings and occassions.
TL;DR: Stick with your argument about the ability, not the game's schemes and how they're played out. So far, you've poorly presented your statement and haven't given any solid reasons why this should be added in. Citizen should not be able to rule out a Jester in any scheme what-so-ever, nor should it be a setting that is souly dependant on GF being immune to RB and Escort being notified of it. Adding a setting that is -dependant- on other roles having a specific setting -enabled- is a poorly constructed idea to implement into the game. If you wish to suggest for settings to be enabled into the game, it has to circle around their CORE function and purpose.
This setting, does not. It doesn't matter how well it adds protection to GF at night in the case of an Escort finding out a RB-immune role -- the escort's goal and objective is to either proactively discover who a killing role is via WIFOM and deduction skills, or rely on the -core roles of the town- to discover the -protective/support- role's goal in order to secure town's victory.
So, in the end: this addition is purely pointless and doesn't add anything to the Citizen. It basically proclaims "I'M A TOWN ROLE THAT'S USED AS A SCAPEGAOT FOR GODFATHER!" when a Citizen is meant to be a scapegaot for TOWN ROLES. Get it now?