A Star Wars fan could also infiltrate the group with the intent of stirring up trouble until the university shuts them down, or the members all hate each other to the point of disbanding, or something. In that case the continued existence of the organisation is explicitly not an interest of that member, and so not a collective interest.
Or if that fan does turn the group into a Star Wars fan club, then the original members will have no particular interest in its continued existence.
A Star Wars fan could also infiltrate the group with the intent of stirring up trouble until the university shuts them down, or the members all hate each other to the point of disbanding, or something. In that case the continued existence of the organisation is explicitly not an interest of that member, and so not a collective interest.
Or if that fan does turn the group into a Star Wars fan club, then the original members will have no particular interest in its continued existence.