This is radical because the Gentiles (non-Jews) were the unfaithful--they were outside of God's covenant. And Eunuchs were unclean; they weren't allowed to worship inside the Temple. God is including those who were outside of the religious community before--those who weren't the Chosen People. God makes it clear that His love is for everyone. All are welcome in His Kingdom. No one is excluded--not the unclean, the unwanted or unloved. The outsider and the insider have their place at the Banquet Table.
Advent is a time for us to reflect on those around us who need to know God's love. Are there people who we might consider not right for sharing the gospel with? Do we unintentionally exclude anyone? Do we think that some people are not good enough to receive Christ's forgiveness? God sent His Son because He loves the world (everyone. No one is beyond the scope of His love). There are people in our neighborhood, school, and workplace who need to experience the joy of knowing God's greatest gift for them this Christmas.