Global rename reads the attachment status (original home wiki, merged, autocreated etc) of each local account, then unattaches those accounts (thus erasing the status), and fires a "recursive" job that renames and reattaches one wiki, then creates a new version of itself for the next wiki. The original attachment status is passed along as an array of wiki => status from job to job.
This means that any job error causes the status of the remaining wikis to be irretrievably lost, and the remaining wikis are listed as unattached. (They are not technically unattached, so nothing breaks, but it makes the UI confusing.) `fixStuckGlobalRename.php` tries to fix this by manually passing in a fake status but only does that for the one wiki it's called on so it doesn't really help. Besides, it's still a fake status.
As a quick fix, `fixStuckGlobalRename.php` should pass the fake status for all wikis. As a proper fix, the status should be stored somewhere safer (the `renameuser_status` table seems like a logical place).