hmm... I die and go into the afterlife presuming I can meet and interact with my parents.
Meanwhile they predeceased me and are in the afterlife trying to get facetime with my two sets of grandparents. Who are trying to catch the attention of my great-grandparents who in their turn are working hard on pinning down my great--great grandparents, who in turn are pursuing THEIR parents...
Unless somebody's keeping a very complicated appointments book I can see this creating difficulties!
Then again, the afterlife will be an excellent place to get the genealogy sorted out. i'm looking forward to finding out if (i) I am more than 1/16th Irish (still not enough to get a bloody passport, apparently) and (ii) if there IS any truth in the rumour that my generation are 1/16th Jewish owing to an ancestor who married gentile.
You nearly had me there, but this is not a simple case of "grains of rice on a chessboard" or "penny for the first nail".
Each individual would only have to keep in touch with their own 2 parents, their own offspring, and occasionally their own grandparents, grandchildren and maybe siblings - more or less the same as they did in life. Yes, there would be twice as many people on each "level", but each individual on each level would not have to interact with everyone on the level above or below.
Be that as it may, in what sense would you be meeting the same person? In life, our personalities are shaped by our needs, desires, challenges, hopes, etc. Especially for older people, the knowledge of, and reaction to, your own mortality and the mortality of the people you love is an important aspect of how you think, feel, and behave.
In an eternal afterlife, which is typically imagined to be blissful and perfect, with no prospect of death or bereavement, no hopes or dreams, we would not be the same people.