God's Restoration

In yesterday's reading of Jeremiah's prophecies against the nations, the prophecies against Moab and Ammon end with a note of hope: "Yet I will restore their fortunes." This is actually a Messianic promise that believers among these nations will be welcomed into the Church. What confuses me is that this is stated for Moab and Ammon but not Edom, Damascus, or Kedar and Hazor. Does anyone know the reasoning for that?