Currently, the option to see your account settings is within the Global Nav permission under advanced - per Permission role. So if the Global Nav is hidden from a permission group, people in that permission group will not have access to their Account settings (including follow settings and email notification settings).
It would be great to have the Account settings permission split out from the Global Nav permission so that Admins who want to hide the Global Nav for permission groups can still have the option for users to adjust their own account settings.