It's not about saved or unsaved, elect or non-elect. It's not about labelling people. Those who are in Christ are timelessly in Christ. As Luther says, you are not a real person until you are regenerated in Christ. Only those who are in Christ have real existence anyway. Everyone else has a shadow of what God intended for life.
So is Christ's sacrifice applicable to all? Technically, it "can be". But that's because it is not about individual acts of sin, but about the quality, character, and activity of the universal sin-condition. But it is only applied and reckoned to those who are in Him.
If the death of Christ did not accomplish victory over all evil/dysfunction, then it was not true victory. But of course it was victory over all dysfunction. Christ, as the incarnation of God's righteousness, fills all unrighteousness with Himself. But that unrighteousness is not filled for those outside of communion with Him.
It's not about separating elect and non-elect, it's about God as the source of all salvation, who timelessly has communion with those in Christ, regardless of "when" "in time" their communion with Him begins. He is beyond time. There is no "beginning" for Him. He "always" knows those who are called by His name.
God does not actively damn those outside of communion. They were already born dead. They remain dead. He is not obligated to save anyone.