Page 124 of the Divine Plan of the Ages (1913 edition) seems to say God foresaw that Adam would sin.
God not only foresaw that, having given man freedom of choice, he would, through lack of full appreciation of sin and its results, accept it, but he also saw that, becoming acquainted with it, he would still choose it, because that acquaintance would so impair his moral nature that evil would gradually become more agreeable and more desirable to him than good. Still, God designed to permit evil, because, having the remedy provided for man's release from its consequences, he saw that the result would be to lead him, through experience, to a full appreciation of "the exceeding sinfulness of sin" and of the matchless brilliance of virtue in contrast with it - thus teaching him the more to love and honour his creator, who is the source and fountain of all goodness, and forever shun that which brought him so much woe and misery.
So Russell taught what JWs would later come to reject - that God knew Adam would sin and it was part of his plan. Russell also claims that Adam's test was no farce and he was given a choice.