In Morgan's "Land Fit For Heroes" trilogy, Ringil does talk about the "pale sun" in the Grey Places, which people there call the "Muhn". But he'd just never heard of the Moon.

Because it had been destroyed, and became a ring, home of the Sky Dwellers. Or perhaps an orbital ring, as Stephenson has it in Seveneves. But there's nothing about a bombardment in Morgan's "Land Fit For Heroes". And that brings up the question about how a Moon breakup would really go.

If the Moon just broke up and did not blow up, the piece might not have been given much momentum towards Earth. In such a case they would slowly spread out in a ring. Their orbits would be stable and would decay outwards ever so slowly, as Earth seeps off their angular momentum.