hardlyOf course, they were forgiven from the foundation of the world, due to the fact He was the Lamb slain from the foundation Rev 13:8
8 And all that dwell upon the earth shall worship him, whose names are not written in the book of life of the Lamb slain[for sins] from the foundation of the world.
All the elect before the cross were forgiven, justified from sin premised on the Cross Work Christ would perform for them in time.
Ephesians 2:1–3 (NASB 2020) — 1 And you were dead in your offenses and sins, 2 in which you previously walked according to the course of this world, according to the prince of the power of the air, of the spirit that is now working in the sons of disobedience. 3 Among them we too all previously lived in the lusts of our flesh, indulging the desires of the flesh and of the mind, and were by nature children of wrath, just as the rest.
Ephesians 2:11–12 (NASB 2020) — 11 Therefore remember that previously you, the Gentiles in the flesh, who are called “Uncircumcision” by the so-called “Circumcision” which is performed in the flesh by human hands—12 remember that you were at that time separate from Christ, excluded from the people of Israel, and strangers to the covenants of the promise, having no hope and without God in the world.