I'm really not sure where WF is going with post #73. Claiming a category that isn't yours is a good way to get instantly CC'ed which is suicidal, so I think it's pretty clear that scum are just going to claim whatever their real category is whenever they claim. I guess scum could claim their partner's category, but then if one of them dies... see Pie's Recycled Roles. Put simply, I don't place any importance on whether a role is verifiable or not, unless that role is exceedingly unlikely to be scum, like GP's role.
So, a few things to note in order to explain my thinking.
First, the OP says this:
7 of the following 9 Role Categories belong to the town. Mafia will have role options to pick from not on this list however.
We know there are two role categories that are not included among town roles. We know from the sign-up page that this is true:
How this will work, is this will be an open set up game, with a list of 9 role Category types IE (Investigative, Protective, Manipulation, Preventative" Etc. I will be lying about two of those role categories being in the game, only mafia will know which two categories I am lying about, the other 7 will be truthful.
So, scum will have two choices: they can either claim a role that fits one of the two Categories that they know town doesn’t have, or they can claim a Category that they know a townie will have. Like you said, they’ll get CC’d if they do the latter, so they’ll do the former.
The issue there is that Luna said there are two Categories he’s lying about. He didn’t say scum will have access to roles in those Categories, only that they have role options “not on this list”, which means their actual roles are likely either from one of those 7 Categories town has in its repertoire, or from a Category outside the 9.
So, it follows then that they will have to claim a Category for which they will almost certainly not have an associated role. They could still “confirm” themselves using a different role and making it look like they’re something else, but my point still stands that the setup shouldn’t allow for scum to fully confirm a role from their fake-claimed Category. Maybe I’m just misinterpreting something and Luna has given scum not just two fake Categories to claim but actual roles that slot into those Categories neatly. However, that’s not how I’m reading the above quotes.