When did God NOT know that which was/would be written in the Bible?
How could anyone possibly know what God knows, or when He knew it?
I only have one point. We who are currently "anchored" within this reality we call four dimensional space/time have a tendency to think in terms of causality - cause/effect. But causality itself is part of what God created.
IOW, by pre-existing "all that there is" - He not only is beyond space and time but also causality (and every other physical or phenomenal thing).
It follows that the first cause was Himself, His own will. Likewise, the final cause is Himself, His will.
My two cents - since Jesus, His only begotten Son, is first in everything (Col 1, John 1, etc.), the beginning and the end, and everything is created by Him and for Him (Col 1, Revelation, etc.) - that the Father's will was evidently that He have a family (first cause, final cause). The creation, existence in every sense of the word (spiritual and physical, heaven and earth, etc.) follows to raise up that family, i.e. the new heaven and earth (the effect of the final cause).
Perhaps the Israelis being freed from Egypt can shed some Light on this? Though He already knew that Pharaoh would let them go, the manner in which He had them freed was to reveal Himself in increments evidently so that they would know they are His chosen and make an informed decision whether to believe/trust Him. Likewise, He could have led them straight to the promised land, but instead He brought them time and again to the point of having to make the choice of believing/trusting Him.
He certainly could have manipulated all of their hearts and minds - as He did in hardening Pharaoh’s heart - to "make" a family. Or better yet, He could have created a perfect family from the beginning - skipping the first cause (and effect of this heaven and earth) and moving directly to the final cause (and effect of the new heaven and earth).
That He didn't indicates that He wants all of His family to be comprised of members He chose and who choose Him, love Him and want to be a member of the family no matter the cost.
IOW, causality itself is His will.
Anyway, that's my two cents...