I don't have children myself, but I can speak from the perspective of living in a home with an A and a dad who stayed together. I often hoped and prayed for my father to move us out of the home and never understood how he thought it was better to stay together "for the sake of the kids." Had he taken me out of the home, I can absolutely picture myself feeling mostly relief at not having to live with my mother anymore.
I am sure they are feeling many things. The best way to find out might be to ask them?