I don't think it happens very often. Maybe if the estrangement happened because of one big thing , perhaps that one thing could be rectified . But in many cases ( my own family comes to mind) it just goes on and on, and people adjust to the "new normal". Nothing happens to force a change so life goes on in a different way.
In my family, it was my two sisters who were estranged. After about 20 years of this, one sister ( the one who hadn't instigated the estrangement ) made a big effort, turned up at our mother's place when the other sister was there and made a sort of planned speech about how painful the estrangement was , how much it had hurt our parents and how she wanted to become friends again. My other sister wanted none of it and said that she had no intention of "making up". Even my mother chimed in and said it was all too late and she couldn't see the point of "rehearsed speeches" on the matter. We all went back to what passed for normal, and life went on. About 10 years later the sister who'd made the speech, died and even at that point my other sister never spoke to her.
So no, estrangement doesn't always end in reconciliation. Not in my experience anyway, OP.