Thanks for the link, it is always helpful. They state -
No. Many millions who lived in centuries past and who weren’t Jehovah’s Witnesses will have an opportunity for salvation. The Bible explains that in God’s promised new world, “there is going to be a resurrection of both the righteous and the unrighteous.” (Acts 24:15) Additionally, many now living may yet begin to serve God, and they too will gain salvation. In any case, it’s not our job to judge who will or won’t be saved. That assignment rests squarely in Jesus’ hands.—John 5:22, 27.
No scripture is quoted to support the claim that only those living now who are serving God will gain salvation and since there is none, they are doing the judging for those living now, rather than Jesus.