DC, My wife confirms that her family and the Italians of her hometown of Pittston, PA (the Tomato Capital of the USA) always referred to the sauce as gravy. I woke her up to ask her this, so I received no further details.

I've known her and her family since 1985, and eaten many pasta (oops, I mean macaroni) dinners there, but I've never heard them say gravy, but she says it was commonly called gravy, so I believe it.

It still seems odd to me as gravy is what I put on mashed potatoes and turkey. But I learn something every day.