Only if the wpForReUpload parameter is set, the license input is hidden. This is IMHO also wrong behaviour of the upload form. It should hide the license input if the wpDestFile parameter is set to something for which a file description page exists. And only then. The wpForReUpload parameter is good for suppressing warnings but that should be all it does.
|mediawiki/core||master||+91 -10||Upload form: Show or hide form controls dependent on existence of destination|
Make sure the interface makes sense if someone does not realize they are uploading to an existing file name. A clumsy solution would be showing "You are about to upload a new version of an existing file. License selection has been disabled." in place of the selector.
@Rillke: Hi! This task has been assigned to you a while ago. Could you maybe share an update? Do you still plan to work on this task?
If you do not plan to work on this task anymore: Please consider removing yourself as assignee (via Add Action... → Assign / Claim in the dropdown menu): That would allow others to work on this (in theory), as others won't think that someone is already working on this. Thanks! :)