[Sam Bauers]

Go to the WordPress integration options page in the admin and set the user roles at the bottom of the page. Doing so will update any existing users lacking roles in either WordPress or bbPress.

Once the user role mapping is set it will add roles to WordPress as well as bbPress from then on when a user registers in bbPress. WordPress registrations is another matter though, I thought a subscriber would have defaulted to being a member in bbPress. I.e. if they had user data but no role the default is to make them at least a member. Can you check this?