The Watchtower people speak out of both sides of their *mouth* on this one.
They say that anyone who dies before the judgement of Armageddon has the opportunity to be resurrected, but Jehovah and Jesus are the judges as to whether they had a thorough witness given to them. Even then, they must have blasphemed the holy spirit in some way to be rejected for a resurrection to stand judgement by God.
The basic teaching is that death pays for our inherited sins, but some may have deliberate sins when they knew better than to blaspheme the spirit they way they did.
BUT the real reason they do make huge allowances for people to be resurrected if they died before Armageddon is so that the JW's don't leave over their non-JW family's deaths. If a mother loses her son or a daughter loses her mother in death, Watchtower teachings allow them to believe they have to remain faithful to Watchtower in case Armageddon comes. It is the only way they will be able to see that son or mother in "the new system."
Some would fall away if they were told they can hang it up for Grandma or Grandson being resurrected. They would rather die too.
Or in short: It's a cult.