Morning KJV,
Regardless of Abraham's children, scripture is clear in that God is in now wise done with ethnic Israel. Rev.12:6,14 demonstrates that in the middle of the seven years the abomination will set up in the holy place within the temple. This in turn will cause the desolation of Israel who will flee out into the wilderness at a place where they will be cared for by God during that last 3 1/2 years, referred to as 1260 days and a time, times and half a time.
That said, God would not be caring for ethnic Israel during the great tribulation if He didn't have plans for her. Jesus will be ruling from Jerusalem and will be the ruling nation during the millennial period.
There is also a matter of the future event of Ezekiel 38-39, when the nations referred to as Gog and Magog and the nations with them, come against Israel where God causes every man's sword to be against his brother. That entire army will be wiped out without Israel lifting a finger. The question is, if God was done with ethnic Israel, why would he fight for her and and show himself holy to the nations of the world and that He is the God of Israel?
There are many other scriptures that demonstrate that God still has unfinished prophecy with Israel and is therefore still their God.
In addition, we have a description of a temple in Ezekiel 40-48 with dimensions that do not fit any of the previous temples. Included are land allotments that do not match the previous locations. This temple is much bigger than the preceding temple. This means that this is a future temple and the only place that you could find fulfillment is during the millennial kingdom.