Undeniably so, except that there was no agreement by the whole Church as to when the child was "ensouled." Tertullian believed that human life (soul) started at the moment of conception, that the product was human from the start. Others thought and taught otherwise.
It was this disagreement that led to the development of the doctrine of the soul in the Church. Blessed Augustine, for example, was unsure as to when the product had life. He argued that what has no life cannot be killed.
Ancient Church knew that aborted embryos in the first trimester, especially those in the first week of pregnancy, could not breathe on their own and appeared dead on arrival.
They also didn't "look" human. Many of them had gills, and other non-human elements which only straightened the belief that the product was in the process of being complete but was not complete, and for that reason had no life (i.e. couldn't breathe on its own).
Thus, an aborted fetus in the early pregnancy was believed not ensouled yet; as such, abortion was not murder at this stage; the child was not a child, and wasn't 'killed' because it was never alive.
Apparently, the idea that the child would have been able to breathe on its own if it were not destroyed never entered the discussion! As far as the Church was concerned, no murder took place. Even if the interruption of pregnancy was considered unnatural interference (like contraception is today), and as such a sin, the gravity of early abortion did not have the stimga or murder.
It was not until the 1700's that the Church (in part due to advances in medical knowledge) finalized its position on when life begins. In her 1700 year-old history the Church, individual exceptions notwithstanding, did not consider first trimester abortions as murder.
The Church never, to my knowledge, defined the relationship that exists between the social teaching of the Church and the theological dogmas
The only dogmas are those beliefs acclaimed as incumbent on all members of the Church by an Ecumenical Council, not what a local church decides to teach in a given political and social environment.
Resistance to abortion by the Orthodox is based on the core principles of the Christian faith and does not need to be stated as a separate teaching, or "dogma."
I don’t disagree with your post, and indeed to separate the teaching on abortion from the totality of the doctrines of the Church is incorrect.
The development and deepening of the understanding of when life begins is not a solely theological question. Ensoulment hypothesis was an attempt to understand fetal development, that is now obsoleted by science. We know what constitutes a human being; in the Middle Ages, they did not.