In the Genesis Experience Heavenly Father commanded Adam and Eve to "Be fruitful, and multiply, and replenish the earth" Gen. 1:28 KJV and also commanded them to "Of every tree of the garden thou mayest freely eat: But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die." Gen. 2:16-17 KJV
My understanding is that these commandments where in opposition to each other. First they where commanded to be fruitful and have children and families and multiply. But how could they do that being in a state of inocience, like children, and not knowing how? "And now, behold, if Adam had not transgressed he would not have fallen, but he would have remained in the garden of Eden. And all things which were created must have remained in the same state in which they were after they were created; and they must have remained forever, and had no end. And they would have had no children; wherefore they would have remained in a state of innocence, having no joy, for they knew no misery; doing no good, for they knew no sin. But behold, all things have been done in the wisdom of him who knoweth all things. Adam fell that men might be; and men are, that they might have joy." 2 Ne. 2:22-25 B.O.M.
So basically the only way they could keep the first commandment was to transgress against the second commandment. If they kept the second commandment then they where not fulfilling the first commandment of having children.
"And to bring about his eternal purposes in the end of man, after he had created our first parents, and the beasts of the field and the fowls of the air, and in fine, all things which are created, it must needs be that there was an opposition; even the forbidden fruit in opposition to the tree of life; the one being sweet and the other bitter. Wherefore, the Lord God gave unto man that he should act for himself. Wherefore, man could not act for himself save it should be that he was enticed by the one or the other." 2 Ne. 2:15-16 B.O.M. There had to be this oposition for there to be free will or agency.
In my opinion I believe Heavenly Father new eventually Adam and Eve would pertake of the fruit and die not only physically but also spiritually by being cut off from his presence. We dont know how long Adam and Eve where in the garden it could have been hundreds of years or thousands before they took of the fruit. The great news of this experience is that we have been redeemed from the fall through the atonment of Jesus Christ, and even though we might die physically we will live again and be resurrected because of the resurrection of Christ.