Yes, Adam & Eve will be forgiven for their original sin. That is exactly the reason why Jesus came to the earth, to die for Adam’s sin and to release him and his entire family from the prison of death.
Adam and Eve, created with perfect physical bodies, were inexperienced with evil. They made the wrong choice by disobeying God. They, therefore, had to experience the consequences of alienation from God, suffering and death. In the 900+ years Adam lived, he gained invaluable experience and appreciation for the consequences of disobedience. When Christ resurrects him from death, he will likely be glad to make the right choices. The rewards for his new obedience will be perfect life on the earth. It will be life full of thanksgiving, heart devotion, and harmony with God.
ALL people who ever lived will be coming back from the grave, all including Adam & Eve: 1 Corinthians 15:22, “For as in Adam all die, so in Christ, ALL will be made alive.”
1 Timothy 2:5-6, “For God is one, and there is one Mediator of God and of men, the Man Christ Jesus, who gave Himself a ransom for ALL, to be testified in due time.”
A ransom, or corresponding price, was a perfect man for a perfect man. The first man (Adam) sinned and was condemned to death, the second man (Jesus) came to die and pay the penalty to release the first man from the condemnation of death. So, yes, Adam and Eve will certainly be forgiven in the resurrection. Hebrews 10:17, “And their sins and iniquities will I remember no more.”