The New Covenant is based on better promises and one of those promises is that Israel would never cease to be a nation before God (
Jeremiah 31:35-37), so that does not leave any room to interpret Romans 9 and 11 as saying that God is not currently dealing with Israel. In
Exodus 12:38, there was a mixed multitude that came up out of Egypt, so there were Gentiles at the foot of Sinai, and in
Joshua 8:33, Israel was inclusive of both the foreigner and the native born, so Israel is inclusive of all Gentiles who have faith in the God of Israel. In
Ephesians 2:12 and
2:19, through faith in Messiah, Gentiles are no longer strangers or aliens, but are fellow citizens of Israel along with the saints in the household of God. In
Acts 15:16-18, they considered the inclusion of Gentiles to be part of the the restoration of Israel in fulfillment of prophecy. In
1 Peter 2:9-10, Gentiles are included as part of God's chosen people, a holy nation, a royal priesthood, and a treasure of God's own possession, which are terms used to describe Israel (
Deuteronomy 7:6).
In
Romans 9:6-8, Israel is composed of all those who have faith in the promise. In
Matthew 4:15-23, Jesus began his ministry with the Gospel message to repent for the Kingdom of God is at hand, which was a light to Gentiles, and it is by the Torah that his audience knew what sin is (
Romans 3:20), so repenting from our disobedience to it is a central part of the Gospel message, which is in accordance with Jesus being sent in fulfillment of the promise to bless us by turning us from our wickedness (
Acts 3:25-26), which is the Gospel that was made known in advance to Abraham in accordance with the promise (
Galatians 3:8), and which he spread to Gentiles in Haran in accordance with the promise (
Genesis 12:1-5). In
Genesis 18:19,
Genesis 25:4-5, and
Deuteronomy 30:16, the promise was made to Abraham and brought about because he walked in God's way in obedience to His law, he taught his children and those of his household to do that (which is in accordance with spreading the Gospel that was made known in advance to him), and because the children of Abraham did that. In
John 8:39, Jesus said that if they were children of Abraham, then they would be doing the same works as him, and in
Psalms 119:1-3, the Torah is how the children of Abraham knew how to be blessed, so the way that the children of Abraham are multiplied and are a blessing to the nations in accordance with faith in the promise is by turning the nations from their wickedness and teaching them to obey the Torah in accordance with spreading the Gospel, which is what composes the body of Christ (
Galatians 3:26-29).