Whatever you do should be according to your own objective and self-integrity. Allow me to present the following three possibilities:
1. If you just want to avoid being disfellowshipped at all cost, then either
-- avoid the meeting altogether, or
-- allow the meeting, but be at their mercy and just give the standard "Sir, yes sir!" response to everything (it's okay to just switch your brain to the "off" mode in that case).
2. If, on the other hand, you don't really care about being disfellowshipped (or judged to be not an "approved associate" if you were never baptized) and the consequences that would entail, then
-- in that case, I would familiarize myself with all the pertinent issues relating to the trueness and authenticity of the Governing Body's claims of being the sole mouthpiece for God (right from Russell down to the latest change of the FDS comprising just the current GB) and let them have it from both barrels right in the face - BOOM!
3. The third option: if you want to be reasonably careful about avoiding being disfellowshipped/disassociated and want to keep your family together BUT you would also like to stand up for yourself and stand up for the idea of fairness, justice, and open-mindedness, then
-- in that case (which is the one I would be more inclined to choose myself), I would allow a brief meeting but I would just say to them something like, "Oh, and by the way, I was just wondering about a couple of things I was curious about that I thought perhaps you could shed some light on . . . ," and ask them, in somewhat of a matter-of-fact manner, about the missing Jesus in the April 15, 2013 Watchtower (I think that's the one) and also the change at the October 2012 annual meeting about the FDS comprising just the current GB, and, without raising suspicions or seeming dogmatic about it, just leave it up to them to give you an answer. This approach would at least give the elders, as well as your wife, something to at least think about; it would plant a little seed in their minds which they would have to come to terms with personally. If they ask you directly whether or not you believe that the GB is God's sole spirit-anointed organization, you don't have to answer either Yes or No but, instead, you could just say something like, "Don't get me wrong, brothers, I would certainly like to believe whatever the truth is, but to be honest I'm not absolutely sure given certain new technicalities I've become aware of, and I would welcome any thoughts you might have based on solid evidence." So, instead of just sticking your neck right out for them to chop it off, I would still give them something to think about - and put the burden of proof on them. If they really are intelligent and reasonable people, they should be able to offer you at least some little crumb of insight on these matters, and if (when!) they just end up putting their foot in their mouth, then, . . . . Voila!