I see what you are saying. I feel that Paul is speaking collectively of the church and christians when He says that things are predestined. That Christ does have a purpose for his church. Which I agree. I do not feel that it refers to individual persons. And again. God knows what’s going to happen, but doesn’t choose for us (I know you aren’t stating that, but I wanted to state it again).
If God is all-knowing (and He is), then He can’t know a group (like the Church) and not know its members. If He doesn’t know its members, then He is not all-knowing.
He IS all-knowing, so He does know its individual members.