The Genesis story was first told to people whose world was literally being destroyed before their horrified eyes. And when the Israelites heard about the formless void, they already knew what it was. It's the unexpected death of a loved one. I'm sorry, but I'm afraid it's malignant. Creation is not something that was finished 10,000 years ago or a billion years ago.
Creation is a work in progress.
It's going on right now, right here in our midst. God never stops being creative, never stops wrestling with the formless void. God keeps bringing something out of nothing, creation out of chaos. People in exile, having lost everything, need to be reminded that God is still in control, that God is still actively involved in creation, still bringing something out of nothing, still battling chaos in all its various forms. The Good News is that God continues to wrestle with the formless void, bringing something out of nothing.