Goy means nation, people, or Gentile. Appearing over 550 times, it initially referred to any nation including Israel. Over time it came to denote non-Israelite nations — the 'Gentiles' — often contrasted with am (people of God).
God's plan always included the nations. Abraham was blessed to be a blessing to all goyim (Genesis 12:3). The prophets envision the nations streaming to Zion. Paul declares that in Christ the dividing wall between Jew and Gentile is broken. The Great Commission extends God's reign to 'all nations.'