On the day of Pentecost 33 CE when Holy Spirit came down in tongues of fire on the first century Christians, the apostle Peter quoted Joel’s prophecy that their would be an outpouring of Holy Spirit before the Day of Jehovah. That day of Jehovah happened in 70 CE.
There is another Day of Jehovah going to take place in the future. It would be logical that before then, there would be another outpouring of Holy Spirit. Jehovah’s Witnesses would be in an ideal position to receive the anointing because they don’t claim to be anointed already but at the same time they are loyal Christians.
I think the work they are doing now is a baptism of repentance, a John the Baptist work, leading to something bigger. Maybe a fulfillment of Malachi 3. Elijah preparing the way and the messenger of the covenant coming to the spiritual temple.
If their is an outpouring of Holy Spirit that would be the birth of the New Spiritual Israelite nation, it could be likened to the fig tree putting forth leaves. And it’s the generation that sees the birth of the nation, sees Armageddon.
(See also Ezekiel 37)
The 144,000 is figurative.