Sorry, I wanted to answer to this thread for a while.
Chre, have you tried with:
 grep -r Last-Translator . |grep .fr.po
in the tails repo?
Or maybe if you already have the file, lets say, 
https://git-tails.immerda.ch/tails/tree/wiki/src/about.fr.po , you can go through the commits to that file and see if there is any change of translator: 
https://git-tails.immerda.ch/tails/log/wiki/src/about.fr.po
Incidentally, I opened 
https://github.com/WeblateOrg/weblate/issues/1604 and 
https://github.com/WeblateOrg/weblate/issues/1661 that are similar, maybe you want to chime in?