This topic is something I have been thinking about for a while.
I think that should something major happen to the Society we will see a wave of depression, anxiety and suicide the likes of which we’ve never seen.
I am sure it will be bad, but I doubt there will be large numbers of suicides. I think it will be similar to post-1975. A lot will leave and a lot will find some other reason to continue to believe. Another historical guide is the "Great Disappointment" of 1844. After the Great Disappointment, instead of disbanding, Millerites went on to form the Adventist churches.
I expect that most Witnesses will eventually (or sooner) find somebody to tell them what to do. It would not be difficult for somebody (perhaps even the current governing body) to set up a new religion that looks very much like the old one. We’ll still be fighting the same enemy, he’ll just go by a different name.
Yes, this worries me the most. Borg ver 2.0 will have a free hand to ditch the inconvenient aspects of its history and iron out the flaws in its theology. Borg ver 2.0 might be more difficult to deal with.
However, Borg ver 2.0 will have some major hurdles. Firstly the current Borg is busy consuming all the cash and assets, selling surplus Kingdom Halls, etc. There may be less and less infrastructure available for Borg ver 2.0 to use. Secondly, the very centralised style of religion where everything globally is micromanaged from New York would be very hard to re-create in a relatively short period of time, and it would be a very daunting financial risk for even a member of the GB to try to do.
In any event, even though I thing the Borg has serious long-term financial issues, I am not expecting the Borg to collapse in the near future.