We have installed the opt-out add on, but having problem viewing the subscription status from user’s subscription section. Only one user can view the “global forum notification” category from its subscription page(I assume this is where you can see people’s opt-out status on notification emails).
The Global Forum Notification option in the bbPress profile screen only shows to people belonging to a role that has been selected to receive notifications under Admin -> Forums -> Email Notifications.
Please double check which roles have been selected. People within those roles will be seeing the option.