Oh, I'm sorry. Thank you for your explanation.

I acknowledge that some tasks are better done outside the content translation tool, but this can easily be abused since it's possible to move userspace drafts into article namespace pretty easily. Therefore, I'm against not putting those articles in the tracking category. If it's possible to change whether the articles are put in the tracking category depending on the user (with administrators given the right to change that), that would be fine though.

Although making it possible to delete the old translations completely IS a solution to this, there's another bug with the error message, which I think should be settled as a different matter from the merged task.
I had never used that function before, but there WAS a button to restart the translation from scratch when the original became old.