I will NOT dispute this statement. As the Heavenly Father told Jeremiah that 'Before I formed thee in the belly I knew thee; and before thou camest forth out of the womb I sanctified thee, and I ordained thee a prophet unto the nations." To know someone before birth in this flesh body means the soul has a history, it cannot be a figment of imagination. Same as with what is said about Jacob and Esau before either ever having been born in flesh bodies to do good or evil, Jacob I loved but Esau I hated.
So it stands to reason that who we are in the flesh is a reflection upon who we were in the first heaven/earth age (IIPeter 3: whole chapter), wherein there were no flesh humans. But in that demonstrated transfigured body of Moses and Elijah. Flesh eyes cannot see in that dimension unless an act of the Heavenly Father gives sight. Say like the example given to us when Elisha prayed in response to the servant in fear when he saw the host compassed the city. IIKings 6:14-17. And reason why Paul speaks of predestination before the foundation of this world (age). And for the perfection of all justice and fairness to alll souls all would be required to pass through this flesh age to have opportunity to see the Kingdom of God as Christ so stated.
Well, the standard pre-fab answer to this is that God is transcendental and therefore knows and sees everything as "present" (that "eternal [aoristic] present").
The other answer is historic and factual: pagans, Jews and Gnostics believed in the pre-existence of the souls. The Church doesn't. This was one of those points of departure of Christianity with these groups. Now, some cults, such as LDS, spout pre-existence of the souls, but that just makes them members of the same non-Christian club mentioned above.
So it stands to reason that who we are in the flesh is a reflection upon who we were in the first heaven/earth age (IIPeter 3: whole chapter), wherein there were no flesh humans
2 Peter is a 2nd century fraud in my opinion, but it was very useful to the early Church, and now it would be difficult to go back and toss it away. It took the Church a long time to accept is as "inspired." I can see why.
That being said, your particular references has some important, even essential 2nd century Christian material: one is the fact that the expected second coming "before this generation will taste death" had to be redefined to an unspecified time in the future.
It is well known that early Chritsians did expect the second coming of the Messiah within their lifetime as the New Testament suggests.
Dispelling these beliefs and leaving the door open was crucial to the survival of the the Christan sect, so I can see why some in the Church found 2 Peter necessary.
The book was also necessary because of its reconciliatory tone with Paul. The Pauline and Petrine factions of the Church were still at odds with each other despite claims to the contrary in Acts. So the sect took on Pauline garments but remained Petrine inside.
Likewise, 2 Pet is asking people to be patient, to live righteous lives and trust that God will spare the righteous, etc. He reinforces this appeal with threats and imagery of a catastrophic end of the world.
All this was needed to keep the faith going despite some setbacks.
But I certainly cannot find any evidence of "pre-existing" bodiless souls in 2 Pet 3.