The message about activation won’t break anything. It won’t even keep the bridge plugin from working. It simply controls whether you get updates or not.
The screenshot doesn’t show if you have the bbp-private-groups plugin installed and active. Can you please confirm that it is?
The bridge will NOT break bbpnns or private groups. It’s simply not recognizing that private groups is installed and is only writing the message and not doing anything else. Please explain why you think you need to deactivate the bridge for the others to work (how are they not working?).
If you create an admin account for me using vinny [at] usestrict [dot] net I can look into why the activation isn’t working.