Isaiah presents God’s servant as one who goes from the most extreme suffering to the highest exaltation. He truly rises from the bottom to the top, from the last to the first. Jesus reaches these extremes when He goes to the cross to be sacrificed for the sins of the world and then upon His ascension when He went to the right hand of the Father.
In the wake of His exaltation the revelation of who He is and what He has done will spread throughout the world. That is exactly what happened as His disciples took the gospel to every kingdom and made disciples of the nations. Beginning with Pilate, we see how rulers are faced with the power of Jesus and amazed at His righteousness and wisdom. The same would happen with Paul in his trials during his ministry.
Gentiles, in particular, have much to be thankful for because they now have the knowledge of that which was only known to Israel. And it was because of Jesus life, death, resurrection, and ascension that we can know fully what prophets and kings in the past have sought to discover. It’s easy to forget what a privilege it is to know what we know and to have direct access to the throne of grace.