Was the "Angel" character played by Jessica Lange really supposed to represent...

… Joan McCracken, Fosse's second wife, who died very young?

No, Fosse wasn't a widower, he'd dumped McCracken for Gwen Verdon while she was in very poor health, and didn't have long to live. But this came up on another discussion of "All That Jazz", someone said that the "Angel" was not supposed to be a supernatural figure, but someone he'd been close to here on Earth. Which makes a certain amount of sense, she seems to known him very well, and is very... down-to-earth for an Angel.