In a Question from Readers in the Watchtower of 15 August 2014 it says :
For years, our publications have said that Jesus’ words about the resurrection and getting married likely refer to the earthly resurrection and that those resurrected to life in the new world will evidently not marry. [e.g. The Watchtower, June 1, 1987] (Matt. 22:29, 30; Mark 12:24, 25; Luke 20:34-36) While we cannot be dogmatic, is it possible that Jesus’ words refer to the heavenly resurrection? Let us examine what Jesus said.
It then discusses several questions which that raises, including :
Third, if Jesus’ words about the resurrection and getting married apply to the heavenly resurrection, does this mean that those who come back in the earthly resurrection will be able to marry? God’s Word does not give a direct answer to that specific question. If Jesus was, in fact, talking about the heavenly resurrection, then his words do not shed any light on whether resurrected ones on earth will be able to marry in the new world.