Since these sheep are not the Kings spiritual brothers, he does not invite them to sit on heavenly thrones and rule with him for the special thousand years of his reign.Here are the facts:
Jehovah's Witnesses believe that:
a. The "other sheep" of John 10:16 are to be equated with the "great crowd" of Revelation 7:9..( Life Everlasting in Freedom of the Sons of God, p. 364)
By his words inherit the kingdom, he is inviting them to enter the Kingdom era after he has destroyed all the ungodly kingdoms of this world during the war of the great day of God the Almighty at HarMagedon.(Revelation 16:13-16)
Many of the sheeplike ones now living will survive that war of all wars and enter into Christs Thousand Year Reign without dying.
So the King Jesus Christ speaks to these sheep as to his children whose time has come to enter into an inheritance from him. By his death as a perfect human to provide a ransom sacrifice for all mankind, he gave up all prospects of personally enjoying the earthly Paradise.(Luke 23:39-43)
In this respect Jesus,the last Adam, is unlike the first man Adam who sinned and forfeited the earthly Paradise for all his offspring.
Thus the resurrected Jesus Christ, who becomes the Eternal Father of all the redeemed world of mankind, had something to bequeath to these sheeplike ones on earth.(1 Corinthians 15:45; Isaiah 9:6, 7)
The human family was founded in the first man Adam, with all his Paradise prospects and opportunities. But that lost Paradise is to be restored by means of Gods Kingdom in the hands of the last Adam, Jesus Christ.
Not until after they had been driven out of the first Paradise did Adam and Eve begin to have children. Their second son, righteous Abel, was murdered by their first son, Cain. So their son Seth was viewed as taking Abels place. With the birth of such offspring, the world of mankind was founded.
But before this, when the parents of the world of mankind were driven out of Paradise, Jehovah God made his merciful promise concerning a seed that would bruise, or crush, the head of the symbolic Serpent, Satan the Devil. That seed was to be a royal Seed, and this involved a Kingdom, according to Gods purpose and forevision.(Genesis 3:15)