I do not think so.
Paul goes to great lengths to describe what "all Israel" encompasses in Romans 9:6-8:
(6) Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel: (7) Neither because they are the seed of Abraham, are they all children: but, in Isaac shall thy seed be called. (8) That is, They which are the children of the flesh, these are not the children of God: the children of the promise are counted for the seed.
This is rather cryptic. Galatians 4:22-31 helps make sense of this. It says that Ishmael was born after the flesh, but Isaac was through promise which things are symbolic. They represent two covenants (1) Mount Sinai which gives birth to bondage and corresponds to Jerusalem "that now is"; and (2) Jerusalem "above" which is free. We then learn that those, who believe in Jesus Christ, are children of the promise, as Isaac was. And that those born after the flesh persecute those who are "born after the spirit". [To wit: The non-believing Jews persecuted and martyred the early Christians (Jew and Gentile).]
So, "all Israel" consists of believing Gentiles and believing Jews. It does not consist of non-believers, regardless of their fleshly descent. ("Neither because they are the seed of Abraham, are they all children." And "They which are the children of the flesh, these are not the children of God.").
Paul then describes how believers can show mercy to the disobedient [Jew]: For as you were once disobedient to God, yet have now obtained mercy through disobedience, even so these also have now been disobedient, that through the mercy shown you, they may also obtain mercy." (Romans 11:30,31) But the scriptures have confined all under sin, that the promise by faith in Jesus Christ might be given to those who believe. (Galatians 3:22)
But now we are to understand that "all Israel" in Romans 11:26 is every physical descendant of Israel. Hold on. It did not mean this 2 chapters earlier. What's more, in Mark 3:22-30 the scribes from Jerusalem committed an unforgivable sin, "blaspheming against the Holy Spirit". These members of Israel will NOT be saved, ever. Consequently, only "some of Israel" can be saved, not all. Therefore, the phrase "all Israel" cannot possibly refer to whom this article says it does. It refers to the same group in Romans 9:6the saints.
Jesus gave the illustration of the vineyard in Matthew 21:33-43, the meaning of which Jesus made clear when he concluded with saying the kingdom would be taken away from that nation of Israel and given to a nation producing its fruits.
That “nation” Peter spoke to in his first letter. Is God now going to take the kingdom back and return to that apostate nation of fleshly Israel? Hardly.
The king/priests were to rule from heaven not the abandoned Jerusalem.
Didn't this already happened?
Mat 21:9 And the crowds that went before him and that followed him were shouting, "Hosanna to the Son of David! Blessed is he who comes in the name of the Lord! Hosanna in the highest!"