Ok, bringing alma back into it, the prophesy for the Messiah simply says that it must be alma, "a young woman" and not necessarily a virgin, and the other example used for Isaiah 7:14 is often Hezekiah, thereby the claim that Jesus must be "born of a virgin" is pagan...and Jesus isn't the messiah. That's the Jewish claim anyway, but of course nearly every Christian scholar translates it as virgin and the virgin birth is foundational to our faith. In one reading of the same text we can say it means virgin in relation to the Messiah and young woman in relation to King Hezekiah.
The text in Gen 1. is describing the creation of everything, IMO changing the meaning to be anything other than a plain reading and ex nihilo is problematic and leads one to have to question much of the veracity of the entire text.
Different people different traditions. Also we have the Holy Spirit, the largely did not. Also, most did believe in a literal interpretation of the text, some did not of course (just as now), but many - perhaps most even - did. It is not genuine to say that the ancient Israelites did not view Gen. as literal.
Well here, you've resolved your own challenge.
"one reading of the same text we can say it means virgin in relation to the Messiah and young woman in relation to King Hezekiah."
In reality, we don't actually have 1 reading of 1 text. We have 2 readings of 1 text. The original Isaiah reading (which may or may not involve a virgin) and Mathews later reading which involves Mary.
Rather than erasing the old testament with the new, the solution is to hold the two in balance, respecting each in its own light.
Another good example of this issue is found in Genesis 1:26. People say that the "Us" is Jesus and the holy Spirit and the father.
But obviously the ancient isrealites and Moses had no idea who Jesus was, so when they wrote and listened to that, that's not what they would have understood.
And interestingly enough, with the tower of Babel, God says "let us go down and confuse their language", but no pastor gets up on stage and ever preaches about Jesus confusing languages of people at Babel.
And further in Isaiah 6, "us" is used in reference to God and his angels and council.
The point is that, there two two different contexts and two different readings. And I'm sure you know this.
But you can't erase the old testament with the new. Rather you must hold them both, in balance with one another. Understanding that the old testament readers never had the full revelation and thus the old testament doesn't actually say those things.
But simultaneously there is another potential assumption at play here. And that is the assumption that Mathew is not merely using the old testament to convey new truths. But that Mathew is making an effort at re-telling the book of Isaiah.
But Mathew need not be saying that Isaiah was intended to be understood that way (a virgin) by its original isrealite audience. Rather he's only speaking to his later audiences about revelations that he has for people of that later time.