I’ve the same problem.
User Role: Super Admin
Setup: Multisite
WPVersion: 3.5
BBPVersion: 2.2.3
When activating bbpress form my own site I’m not propagated as a subscriber to the other sites.
When I activate bbpress for the main site, the admin site, I become member of that site but no other sites. BUT when I as the network admin list out all the sites I become members of all the sites. So I’m guessing it is a bug.
