That is a very Platonic interpretation of Jer 1:5. The next step is to say we knew the Forms in Heaven, forgot everything because of sin, and throughout life are remembering what we forgot.
I can’t remember if Augustine followed this logic... I have read Confessions and The Trinity, and he does lean more toward Plato and did not like Aristotle at all, but I am not sure if he went as far as a pre-existence of the soul in Heaven. Certainly Roman Catholics have not held that since Aquinas reconciled Augustinian and Aristotelian philosophy.
Had to take a moment to compose a logical thread.
If our souls were not in existence prior to conception, then does it not follow that our souls are a chemically creation? A creation of the joining of an ovum and a sperm? Thus, if our souls were created at the moment of conception, how can we make a claim that our souls are eternal? Further, how can we make the claim that our soul is created by God?
We are taught that our bodies are merely vessels that house our souls for our time during our mortal period. Our mortal bodies are temporary, our souls are eternal. That like Christ, we would know pain, sickness, torment, hunger, weakness and temptation - something that a soul (without a body) would not be able to conceive of. We are told that after we die, and are resurrected we will no longer know illness, pain, hunger or the torments of corruption.
During the Battle of Heaven, Lucifer took 1/3 of the Heavenly Host with him, and they were cast out. Among the 2/3rd who remained were a mixture of the faithful souls, but there were also very likely a goodly number of “fence-sitters” who simply lacked the courage to throw-in with either side.
My faith teaches that 2 plans were offered up to God. Lucifer offered up a plan that souls would live their life on earth and all would be compelled to do good, and by not being given a choice, all would return to God in Heaven, and the Glory of this would go to Lucifer.
Christ offered a plan that the souls would come to earth, and would have free will to do as they would. Some would seek to do evil and would cause great harm to others; while others would strive to do good. Some souls would return to God in Heaven, but many would be lost. Only the truly deserving souls would return - for their true nature would be given reign during their mortal lifespan. Knowing that sin was inevitable, Jesus offered his life as a sacrifice for the forgiveness of all those who would ask forgiveness in his name.
Earth is merely a filter, the stage on which we determine our ultimate reward or our ultimate punishment. Some of us will be rewarded for the choices we made, others will be punished - but we will all be dealt with fairly.