No, it is about being chosen to BE in Christ (the eternal decree stuff).
I don't think it is about that. It is about Christ who is the elect of God. The gospel is about Christ. It is about being in Christ but it is not about people who are not in him, though the message is addressed to all the promises are received by those in Christ because the promise was made to Christ. That's the message that saint Peter presented when he taught
Galatians 3:15 Brothers, listen to this comparison. When anyone has made his will in the prescribed form, no one can annul it or add anything to it. 16 Well now, what God promised Abraham was for his descendant. Scripture does not say: for the descendants, as if they were many. It means only one: this will be for your descendant, and this is Christ. 17 Now I say this: if God has made a testament in due form, it cannot be annulled by the law, which came four hundred and thirty years later; God’s promise cannot be canceled. 18 But if we now inherit for keeping the law, it is not because of the promise. Yet, that promise was God’s gift to Abraham.
The promise is for Christ. Christian participate in it by being in Christ. And Christ is the seed, the elect of God.
1Peter 1:1 From Peter, apostle of Jesus Christ, to all those living as aliens in the Dispersion, in Pontus, Galatia, Cappadocia, Asia and Bithynia, 2 to those whom God, the Father, has called, according to his plan, and made holy, by the Spirit, to obey Jesus Christ, and be purified by his blood: may grace and peace increase among you.
3 Let us praise God, the Father of our Lord Jesus Christ, for his great mercy. In raising Jesus Christ from the dead, he has given us new life, and a living hope. 4 The inheritance that does not corrupt, nor goes bad, nor passes away, was reserved for you, in heaven, 5 since God’s power shall keep you faithful, until salvation is revealed, in the last days. 6 There is cause for joy, then, even though you may, for a time, have to suffer many trials. 7 Thus will your faith be tested, like gold in a furnace. Gold, however, passes away, but faith, worth so much more, will bring you, in the end, praise, glory and honor, when Jesus Christ appears. 8 You have not, yet, seen him, and, yet, you love him; even without seeing him, you believe in him, and experience a heavenly joy beyond all words, 9 for you are reaching the goal of your faith: the salvation of your souls. 10 This was the salvation for which the prophets so eagerly looked when, in days past, they foretold the favor of God, with regard to you. 11 But they could only investigate when the Spirit of Christ present within them, pointed out the time and the circumstances, of this—the sufferings of Christ, and the glories which would follow. 12 It was revealed to them, that they were working, not for themselves, but for you. Thus, in these days, after the Holy Spirit has been sent from heaven, the gospel’s preachers have taught you these mysteries, which even the angels long to see.
And saint Paul also taught it in these words
Ephesians 1:1 Paul, an apostle of Christ Jesus, by the will of God, to the saints in Ephesus, to you, who share Christian faith: 2 receive grace and peace from God, our Father, and from Jesus, the Lord. • 3 Blessed be God, the Father of Christ Jesus our Lord, who, in Christ, has blessed us from heaven, with every spiritual blessing. 4 God chose us, in Christ, before the creation of the world, to be holy, and without sin in his presence. 5 From eternity he destined us, in love, to be his adopted sons and daughters, through Christ Jesus, thus fulfilling his free and generous will. This goal suited him: 6 that his loving-kindness, which he granted us in his beloved might finally receive all glory and praise. 7 For, in Christ, we obtain freedom, sealed by his blood, and have the forgiveness of sins. In this, appears the greatness of his grace, 8 which he lavished on us. In all wisdom and understanding, 9 God has made known to us his mysterious design, in accordance with his loving-kindness, in Christ. 10 In him, and under him, God wanted to unite, when the fullness of time had come, everything in heaven and on earth. 11 By a decree of him, who disposes all things, according to his own plan and decision, we, the Jews, have been chosen and called, 12 and we were awaiting the Messiah, for the praise of his glory. 13 You, on hearing the word of truth, the gospel that saves you, have believed in him. And, as promised, you were sealed with the Holy Spirit, 14 the first pledge of what we shall receive, on the way to our deliverance, as a people of God, for the praise of his glory.
It is in Christ that the faithful receive their calling, their election, their salvation, and in the last day their glorification all in Christ none in individuals apart from Christ.
