Only Isaiah 7:14 was mentioned in Matthew chapter 1 as a prophecy about Jesus, not 7:15-16, etc. So those are not applicable.
There is also the concept of "dual fulfillment" in prophecy, as is explained in the link below.
https://sounddoctrineministries.wordpress.com/2012/01/18/the-dual-fulfillment-of-prophecy/
That being noted, what is interesting to me is that you are unable to identify this very important child in Old Testament Judaism. There was no one named Immanuel that we know of back then. No one born to Ahaz or Isaiah or anyone else that we know of that rose to a level of importance.
I don't believe the high priest was incensed about Jesis claiming to be the Messiah as was his claim that he was the Son of God. From Matthew 26:
The high priest said to him, “I charge you under oath by the living God: Tell us if you are the Messiah, the Son of God.”
64 “You have said so,” Jesus replied. “But I say to all of you: From now on you will see the Son of Man sitting at the right hand of the Mighty One and coming on the clouds of heaven.”
65 Then the high priest tore his clothes and said, “He has spoken blasphemy!
Evidently, at that time in history, and quite possibly based on Daniel 7:13-14, there was a belief among the pharisees that the Messiah would also be the Son of God.