I believe it's a general statement concerning those God foreknew. Before God predestinates a man, he must first know the man as one of his. After knowing a man is one of his, he then determines that man's end result, thus "predestinates".
1 Now I say, That the heir, as long as he is a child, differeth nothing from a servant, though he be lord of all;
2 But is under tutors and governors until the time appointed of the father.
3 Even so we, when we were children, were in bondage under the elements of the world:
4 But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law,
5 To redeem them that were under the law, that we might receive the adoption of sons. The adoption is to which a believer is predestined to. See Ephesians 1:5. It is the redemption of the body. It is a future event.
6 And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father. The Spirit seals us unto the adoption, the redemption. See Ephesians 4:30.
7 Wherefore thou art no more a servant, but a son; and if a son, then an heir of God through Christ.
8 Howbeit then, when ye knew not God, ye did service unto them which by nature are no gods.
9 But now, after that ye have known God, or rather are known of God, how turn ye again to the weak and beggarly elements, whereunto ye desire again to be in bondage? There is a point in time when God knows a man. Notice the phrase, "after that ye are...known of God."