Everybody gets a chance to answer: Before God spoke the very first word of creation, did He know all details of His creation from who would be saved and down even to the last detail of every single thought of all His created "dirt?
A verse for you to consider:
Mark 10:45 For even the Son of Man did not come to be served, but to serve, and to give His life a ransom for many."Now, would you suggest that Christ is the Propitiation for every single person without exception, but only a ransom for many?
I would suggest you look at Rom.5:15 and 19 (as Hank pointed out) where 'many' is used in the place of 'all'
Even so, come Lord Jesus