In the eyes of the historic church, which theory was seen as more biblical, that the fall happened because God foreordained it, or that humanity sinned as a result of our God-given free will?
God foresaw the Fall and permitted it but He did not preordain it. The Fall occurred because of the free choice of disobedience by Man.
Catechism of the Catholic Church (emphasis added):
III. ORIGINAL SIN
Freedom put to the test
396 God created man in his image and established him in his friendship. A spiritual creature, **man can live this friendship only in free **submission to God. the prohibition against eating “of the tree of the knowledge of good and evil” spells this out: “for in the day that you eat of it, you shall die.” The “tree of the knowledge of good and evil” symbolically evokes the insurmountable limits that man, being a creature, must freely recognize and respect with trust. Man is dependent on his Creator, and subject to the laws of creation and to the moral norms that govern the use of freedom.
Man’s first sin
397 Man, tempted by the devil, let his trust in his Creator die in his heart and, abusing his freedom, disobeyed God’s command. This is what man’s first sin consisted of. All subsequent sin would be disobedience toward God and lack of trust in his goodness.
398 In that sin man preferred himself to God and by that very act scorned him. **He chose **himself over and against God, against the requirements of his creaturely status and therefore against his own good…
399 Scripture portrays the tragic consequences of this first disobedience. Adam and Eve immediately lose the grace of original holiness…