God is about keeping His promises to Abraham, Isaac and Jacob. Though He cast Israel out, cut Israel off, He gathers their descendants back again into His Church, and then back into Israel, reinstating them into their original inheritance again, as fully endorsed by The LORD Israelites. They will be surprised, and so will the Judah Jews.
Also, Jesus bride, The Church is brought into His tribal identity, as His body, His wife, which is Judah.
bkmk
Paul loved the Jews probably more than any other Christian writer throughout history. His life consisted of many paradoxes. He hated Christians and loved the Jews, then became one of the chiefest of the Christians. Most of the Jews hated and hunted him for this turn but his love for his true and pure heritage never waned.