Renaming a tag is highly disruptive. For example the city of Edo changed its name to Tokyo. If you have a bunch of files tagged with the string “Edo”, then you need to read each tag file, create a new tag with the new name but same target, add the new tag file, and delete the old tag file.
Unless the file just has a pointer to a GUID for the tag. The tag “name” is just property of the tag object.