Something about the question ringed hollow and I had to think about it a bit. Because the truth is if ones spouse is truly in MLC and not simply leaving the marriage for personal reasons or because of the behaviour of the spouse the apology, like everything else we do, makes no difference. So if it is for personal reasons sure, why not. If it is to again manipulate or control, well then its more denial of reality and trying to pretend there is control when there is none.
Then it struck me what the issue was. I think it is a made up story that somehow if we do xy or z on the way out the door, if we “have our say,” if we do some combination of magic incantations there will be “closure” and we will move on. And I realized it is more denial of reality. It is more attempt to pretend we have control and that we are ok. Because like almost all human affair there is no simple, clean, delineated moment, there is no simple answer. There will be no “closure” to a 20 year or any long term relationship no matter what we do. Divorce or not, apology or not, selling the house or not. And this is true even when there are no kids. When there are kids in common well what does closure look like exactly? This will be with us for a very long time.
We grow and heal when we realize the true nature of ourselves, of our spouses, of our friends. About how we are all imperfect, that there are better and worse ways to exist, but there is no exact answer. That behaviour to others MATTER when they are guided by empathy and gentle care of the other, and words only matter when they are exactly aligned with that. And that our kindness, care and growth is shaped by thousands of small acts and steps and rarely by one specific action or ritual.
I owned my part internally like others have said as I re-examined our 23 years together. I was not perfect, but I was not bad. Nothing that happened came from anything I did. I did not badger, control, direct, demean, list faults nor leave. I had bad moments like we all have had, I said things I wish had never been said in the moment, out of my own pain and lack of self awareness. But they were transitory and my actions were always guided by love and empathy for my wife. So I could apologize for tiny things, but I am proud of our life together and how we treated each other vast majority of the time.
And finally I fear an apology is sometimes nothing more than a whitewash. It simply puts a pin and says “see, I said I am sorry so its all ok now. I may have caused you great anguish and damage but hey I just said sorry, so no problem.” Which I guess circles back to another topic of how hearing our MLCers say they are “sorry” may really not be worth that much after all. Its the damage done that counts.