Also you can argue that the (original) filename itself is part of the metadata. It's useful to have what it was originally called when referencing elsewhere. So where to put this data? in a sidecar file during the rename process or something? We could just use content hash, but then online dashboards to redownload things from vendors, for example, won't necessarily have that there displayed on the page, or when you start downloading it in the browser.
In case it's helpful for anyone else having the issue: mmv [0] means you only have to run the command once to rename every file. It's pretty fantastic.