My understanding is that God only acknowledges people as his children after the thousand year reign (Rev 21: 7)
The JW teaching is that the anointed are adopted as God's children at the time of their anointing, but the great crowd become his children after the thousand years.
w12 p. 11 par 17 (great crowd are NOT sons):
When discussing the freedom that Jehovah has in store for his earthly servants, Paul wrote: “The eager expectation of the creation is waiting for the revealing of the sons of God.” Then he added: “The creation itself also will be set free from enslavement to corruption and have the glorious freedom of the children of God.” (Rom. 8:19-21) “The creation” refers to mankind with the earthly hope, those who will benefit from “the revealing” of God’s spirit-anointed sons. That revealing will begin when these “sons,” resurrected to the spirit realm, share with Christ in cleansing the earth of evil and preserving “a great crowd” into the new system of things.—Rev. 7:9, 14.
w09 10/15 p. 27 (sons are the anointed as a group):
However, Jehovah did not foreordain which individual humans would be adopted as his sons. Rather, God determined that there would be a group, or class, of humans that would rule with Christ in heaven.—Rev. 14:3, 4.
w96 7/1 p. 27 (great crowd are NOT sons):
Do the Holy and its furnishings have any meaning for this great crowd of foreigners? Well, they will never be in the condition pictured by the Holy. They are not born again as spiritual sons of God with heavenly citizenship.
re p. 304 pars 3, 4 (sons are the anointed, great crowd become sons after the 1000 years... "filial" means "of or due from a son or daughter"):
Those who drink of that refreshing “water” must also conquer, as Jehovah goes on to say: “Anyone conquering will inherit these things, and I shall be his God and he will be my son.” (Revelation 21:7) This promise is similar to the promises found in the messages to the seven congregations; hence, these words must apply in the first place to anointed disciples. (Revelation 2:7, 11, 17, 26-28; 3:5, 12, 21) Christ’s spiritual brothers throughout the ages have eagerly anticipated the privilege of being part of New Jerusalem. If they conquer, as Jesus conquered, their hopes will be realized.—John 16:33.
12 The great crowd out of all nations also look to this promise. They too must conquer, loyally serving God until they come out of the great tribulation. Then they will enter into their earthly inheritance, ‘the kingdom prepared for them from the founding of the world.’ (Matthew 25:34) These and others of the Lord’s earthly sheep who pass the test at the end of the thousand years are called “holy ones.” (Revelation 20:9) They will enjoy a sacred and filial relationship with their Creator, Jehovah God, as members of his universal organization.—Isaiah 66:22; John 20:31; Romans 8:21
