There are settings

on
off
user

for each topic, on and off are obvious, but how do my users get "user" to work? It sounds a bit like an indivual choice everyone can make, but without user account I dont get how this is possible?

Right there is no user auth system as of right now for roster 2.0 which would then require you as the admin to make the change.

The settings are accessible for the roster admin in another page in the character info addon config.