Very odd. I've never had an animal lose individual scales that didn't also have some type of trauma. As in, nose rubbing or wounds caused by squeezing through too small of a space. Even the cases of scale rot I have seen don't look like your pictures of the individual scale pieces. The IMG_0870 looks similar to scraped scales on the dorsal ridge. Which would occur when the animal rubbed or pulled itself through a tight spot. Have you added any new cage furniture or has the animal recently escaped by popping the top of its enclosure enough to slip through? If it isn't a physical injury, I'd check the humidity. It's cheap and easy to do with a hygrometer (Amazon has lots of them to choose from). Beyond that a trip to a vet may be necessary. Or you can take the wait and see if it passed approach as long as the animal is healthy in ever other way.
As an after thought, do you have access to a microscope? I'd be curious to see what the sloughed scales look like magnified. Please keep us posted as to the outcome/progress.