brink: “a point at which something, typically something unwelcome, is about to happen; the verge: the country was on the brink of a constitutional crisis | the club has come close to the brink, surviving winding-up orders.” (ODE)
I think a virgin conception (of a male child) would strike anyone as more remarkable than simply a prophetic sign (i.e. it was in some way symbolic, or a metaphor).
Odd, then, that no one in the whole of the New Testament thought to make that point. Certainly, neither Matthew nor Luke interprets it as the “incarnation” of the one true God.
Jerusalem was not preserved under Ahaz, but it was thoroughly compromised.
Jerusalem was preserved under Ahaz. In any case, the point of the name Immanuel was that the schemes of the nations against Judah would not succeed:
Be broken, you peoples, and be shattered; give ear, all you far countries; strap on your armour and be shattered; strap on your armour and be shattered. Take counsel together, but it will come to nothing; speak a word, but it will not stand, for God is with us. (Is. 8:9–10)
So Matthew’s point is that the birth of another boy at a critical moment in Israel’s history is a sign that God is with his people and that there is hope of deliverance. If the original Old Testament meaning, transferred into a new context, makes excellence sense, it has to be preferred, surely, over any supposed “entirely” different meaning.
Simeon’s words were right, but there was no restoration of Israel. It never happened.
So what does Jesus mean when he says, “in the restoration, when the Son of Man will sit on his glorious throne, you who have followed me will also sit on twelve thrones, judging (krinontes) the twelve tribes of Israel” (Matt. 19:28)? Josephus uses palingennesia for the “restoration” of Israel (Ant. 11:66). According to Psalms of Solomon 17:26 the Messiah will “gather together a holy people, whom he will lead in righteousness. And he will judge the tribes of the people that has been sanctified by the Lord his God.”
For Luke this is the fulfilment of expectations regarding the kingdom of God: “You are those who have stayed with me in my trials, and I assign to you, as my Father assigned to me, a kingdom, that you may eat and drink at my table in my kingdom and sit on thrones judging the twelve tribes of Israel” (Lk. 22:28–30). So Acts begins with a question about the timing of the restoration of the kingdom to Israel (Acts 1:6).
It seems pretty clear to me that Jesus believed that Israel would be restored, only under a different régime, and he wasn’t sure when it would happen.