Good question! (we will try to run some tests locally, but may be HQ tell? )
Overall, I believe that this behavior needs to be fixed, and the "old" file added via the text editor has to be deleted right away.
It is weird when one can delete a file, cannot see it, but at the same time he cannot upload an updated version of the same.
This would slow down course development process, and cause some grouch
We have this behavior with regular Add a resource > File, where system recognises that "old" file has been deleted and allows to reload with the same name.
p.s., I do not get the note on the wiki FAQ:
Q: "How can I delete an embedded file previously added using the file picker?" A: There is no need to do anything, as any unused files are detected and then deleted automatically after a period of time. Users cannot delete files manually, since they may be used elsewhere."
How they can be used somewhere else, if we are not external linking to a file from some other repository?
Because of the new 2.0 behavior we are suposed to be uploading right into the "page"/"label", hence there should not be any other association of this particular file with anything else in the course.