Hi Philosopher,
Welcome to JWD.
I concur with many of the other posters who recommend taking it easy on trying to confront your family head on with this.
Having said that, I will guarantee you that there is not an old timer Dub alive who does not have doubts in their heart of hearts. They may barely reveal the doubts but the doubts are there. I know this is true because when I was still in (bailed in 1997), once in a while in conversations with old timers who were elders, or special pioneer couples, or sisters who had been in the BORG for 40, 50, 60 years they would make comments lamenting the fact that they fully well expected to be in the new system by then. The sour taste of 1975 and the change in the "generation" change is taking its toll on the BORG's credibility.
Listen to the comments your family makes. If they make comments that express doubt, disappointment, or uncertainty about when the end will come or the authority of the BORG, take the time gently coax them to elaborate. You may be surprised at what you hear. On the other hand, it's true that when someone wraps their life around something that later proves to be an illusion, it can be devastating and can cause the person to go into denial mode, so they may never respond.
All the best and good luck at a very difficult road ahead.
Cheers,
Alex