Lots of them say they will file, and even when they do, they can't seem to see it through. Mine is that way. I've been hearing about this divorce for 10 years now. I just haven't seen it yet.
The only approach is to detach for your own benefit and understand that if it is MLC, it is a long, hard slog. My personal feeling is that they have to leave to live that exciting life we are keeping them from so they can process what they are doing and stand to lose. Even then, some like Peace's and Job's former husbands just roam the earth like lost souls forever.
You don't have any control. None. He probably doesn't either.
You will find yourself again through this and you will have all the happiness you allow into your life. Look forward, not back. If you meet him on the side of the road someday on your journey, and he looks and sounds like someone you want to be around, then great. Either way, by focusing on you, you win every time.
