For if their rejection means the reconciliation of the world, what will their acceptance mean but life from the dead?
Romans 11:15 ESV

“Their acceptance [means] life from the dead” has the same meaning as Ezekiel’s prophecy of dry bones. God will take what appears to be beyond recovery and restore it to full life, physically and spiritually.

The rejection of the Jews was temporary and partial, as prophesied by the Hebrews in Egypt, Sarah in the houses of Pharaoh and Abimelech, and Rebekah in the house of Abimelech. The repudiation and exile of Israel is always temporary and instructive, never permanent nor merely because God is angry. Every rejection is intended to drive them to repentance so that God can restore them.