When the WTS thinks of God, Jehovah, of course, it automatically thinks of the Father.
This has nothing to do with WTS thinking, the Scriptures say what they say no matter who is reading them...
[14 Then I saw, and look! the Lamb standing on Mount Zion, and with him 144,000 who have his name and the name of his Father written on their foreheads.]
What is the Lamb's name?
What is the Lamb's father's name?
[ 17 Jesus said to her: “Stop clinging to me, for I have not yet ascended to the Father. But go to my brothers and say to them, ‘I am ascending to my Father and your Father and to my God and your God.’]
What is the name of Jesus' God?
What is the name of Jesus' brother's God?