You can imagine that certain questions must have arisen almost immediately in regard to the Jerusalem paradigm and the exaltation of Jesus as the YHWH Angel. Everytime the community would read or listen to stories from their scriptures about the YHWH Angel, they must have wondered how these stories about the Angel were connected to Jesus. It is impossible for me to determine who first raised these questions, but what I do know is that their answers were already known to Paul at the time he became a primary leader and missionary of the Antiochean church. So the Antiochean Christians were definitely discussing it, and had even developed liturgies based on their answers. It is a dominant paradigm in western Syria, Asia Minor, Greece, and becomes the dominant meta-paradigm in Rome and the West. It is not unknown to some of the sources associated with Jerusalem, so whatever was going on, it was communicated between Jerusalem and Antioch.
What was the reasoning? It probably went something like this: if Jesus had been exalted at his death, becoming the YHWH Angel, he must have been the YHWH Angel in scriptures like Gen 16:7, 22:15, Ex 3:2-14, 23:20-21 too. This means that Jesus must have existed as the YHWH Angel before his earthly advent. So it must be that this YHWH Angel descended from heaven and somehow embodied Jesus at Jesus' conception or birth.
This is what the much-debated Phil hymn is all about (2:5-7). Jesus had been in the form of God and did not count equality with God a thing to be grasped. This is a reference to the YHWH Angel who is God's manifestation or equivalent. This divine being empties himself and is born in the likeness of men.
Next time we will discuss the virgin birth.