How do you imagine this playing out. Let's say Eve didn't eat and so we didn't fall into sin.
The whole story is nonsense from beginning to end but according to JW's the issue that Satan brought to the forefront was God's "universal sovereignty" and needing to prove to the myriads of angels that God had the right to rule.
Satan tempted Eve with the fruit but even if she refused, by his actions Satan had challenged Gods authority and even told Eve that she could be like God herself and would not die. When God eventually confronted Satan about this matter, Satan likely would have made the same challenge, that of being able to turn everyone away from God. If God destroyed Satan there and then, just as in the original story, it would have looked as if he was afraid of Satan. If "universal sovereignty" was the real issue, he'd have had to let Satan continue in order to give him time to prove himself without any interference.
The only way the human race would win out in this scenario is if Adam and Eve were able to have at least two perfect children before someone succumbed to Satan's devices.