While my parents were not addicts, both my brother and I recognised ourselves in the ACOA profile only a couple of years ago. I'd turned into an emotionally shut down, isolated, overachieving codependent and he'd been a homeless crack addict for years as a result of our severely emotionally and physically abusive childhoods. I feel for your anguish as I watch my brother come to terms with the effects of his behaviour on his 2 daughters who are now 19 and 21.
He'd left his wife and girls a decade ago amidst much chaos and confusion, and was not there for them. He is now in rehab and knows that he was caught up in intergenerational trauma, which he passed on to his girls. He has reached out to them, and I continue to tell him that the best thing he can do is to work on his 'stuff' and be open/available to his children should they need to ask him anything or talk to him about their childhoods. While they haven't visibly acted out, it's clear to me that their social/relational skills have suffered, and that they've shut down their rage over what happened to them. The parentification is very strong in them, just as it was for my brother and me.
My dad was diagnosed with dementia 8 years ago, and there will never be any accountability for his rages and unpredictable beatings. While my mother does acknowledge that she was responsible for so much of our suffering, she has a personality disorder and buffers the terrible reality of what she did with religious convictions. While she's told us that she's sorry, that it wasn't our fault, and that we'd done nothing wrong, she is unable to actually explain why she did the things she did and cannot provide any coherent explanation for her behaviour or state of mind.
Her apologies are motivated primarily by her religious convictions that confessing sins guarantees forgiveness. After all, God ostensibly forgives everything as long as you say you're sorry, right?
I'm not prepared to forgive my parents for what they did, and I focus on MY recovery and salvaging what I can from a stolen childhood and decades of loneliness and emotional anguish. You can't control how your children will respond to your efforts to reconnect. But the chances are far, far higher that your genuine commitment to do your own work, your willingness to reach out, and your openness about what happened will result in new bonds being created. I wish you well in your arduous journey and the possibilities for SUCH a different emotional existence life for yourself and for your children as well!!