If you tell a slave that he is being freed him primary joy is going to stem from the fact that he is no longer dependent on others. What is strange is that when the Torah describes the freeing of slaves in the year of Yovel [ויקרא פרק כה] it says ואיש אל משפחתו תשובו - A man will return to his family. Returning to his family is seemingly secondary to his main feeling of satisfaction that emanates from the fact that he is now a free man and not bound to the whims and desires of others. It MUST be that if the pasuk mentions it then the return of the עבד to his family is what defines his freedom.
The Hebrew word for freedom is דרור. The Rishonim explain that it connotes a sense of permanence. דרור means דור הולך ודור בא - a generation comes and a generation goes. דור - generation, connotes constant movement. The word דייר means tenant. A tenant and not a landlord. A ball is a כדור - which can also mean "like a generation". It rolls and rolls. [Talking about כדור I would like to express my sympathy to Yankee fans. There is always next year. אין שום יאוש בעולם כלל.] Constant flux and change. The word דרור is דור with the letter "reish" twice. A doubling of a letter means a strengthening of the concept. So if דור is constant flux then דרור is the stability and constancy that underlies all change.
That is why the Torah calls freedom דרור. The unchanging status of man is that he is free. We were created ישר to go straight with Hashem. כי לי ישראל עבדים - We are Hashem's עבדים and not anyone else's עבדים. Only because of man's wiles and crookedness [אני עשיתי את האדם ישר והם בקשו חשבונות רבים - קהלת] he stole, went off the straight path, and was sold as an עבד and thereby lost his freedom.
Yovel restores man to his pristine, unchanging state of freedom and is thus called שנת דרור - the year of complete freedom and stability. The fields are returned to their original owners and slaves are released from bondage. Since this is the time of restoration and return to the source, the Torah adds ואיש אל משפחתו תשובו - men return to their families.
עפ"י אגרות פחד יצחק עמ' כח
ואולי ניתן להוסיף על דברי מרן זצ"ל שגם לעתיד לבוא כאשר האדם יחזור לטהרתו המקורית ויצר הרע ישחט, הנביא מוצא לנכון לתאר שיבה למקור וחיבור שני אלמנטים שהופרדו עקב מרירות הגלות - כנאמר במקרא קודש "והשיב לב אבות על בנים ולב בנים על אבותם" ויה"ר שנזכה להתגשמות הנבואה בקרוב אמן כן יהי רצון