If you would like to use "Save as Cloud Model" or "Collaborate with BIM360 Design" and you regularly receive updated Revit models from an outside source, the only way to keep the version tracking is to upload. It would be nice if I could save over the already existing model and have the version increment. Currently, when using "Save as Cloud Model" or "Collaborate with BIM360 Design" Revit will not let you save over if a Revit file with the same name exists.
Another use case for this problem is if you are having unforeseen software glitches or struggles with opening the cloud hosted model but have local copy or are able to download the latest published model, it would be nice to save over and keep version tracking intact.