It’s YES!!!
Omniscient is ALL knowing. What part of *all knowing* don’t you get? All is all.
God is outside of time.
If there were something outside of God, then perhaps one might be able to conclude that He might not know it, but if everything is contained within God, so to speak, how could He NOT know it?
If there was never a point in either time or eternity where God did not know everything, past, present, and future, then why did God have to look down the timeline to determine who was going to choose him so that he could then, in turn, choose them?
If God had to look down the timeline to determine his elect, then one would have to conclude that at some point in time or eternity, God did not know who was going to choose him.
Do you believe that God’s selection of you to follow him was based upon his looking into the future and discovering that you were going to follow him?
Or did you choose to follow him because he first chose you to be one of his followers?