The GB is bluffing. They get it wrong from the beginning.
The purpose of God in not paradise on this earth, it is the transformation of men into a new creation. This is also the purpose of the 1000 years kingdom - to decide who gets transformed into the new man. Some will be transformed at the beginning of the 1000 years, some at the end, after the last judgement.
Jesus was resurrected as the new man, He was the first one of this new creation. This is the reason why jw's can not explain what happened with Jesus's body, and they came with that explanation of Jesus materializing himself, taking different bodies. They do not get this idea of a new creation and a new man that the letters of the apostles talk about. Jesus talked about this in metaphors and parables, because this was part of the sacred secret revealed after the resurrection of Jesus.
Paul says if the sacred secret would have been known before, the authorities of this world would not have crucified Jesus. The big surprise was that Jesus was resurrected as a new kind of man, immortal and indestructible. This is the way the saved ones will be resurrected. But there will also be resurrection for people who are not yet saved, the unjust, those will be resurrected as normal humans, of flesh and blood, as we are now.