I tried running Auto Wiki Browser on https://desencyclopedie.org (a French-language version of Uncyclopedia) to do a relatively simple search-and-replace of {{VBO}} to {{BO}} on a list of a little over 400 pages which were promoted to Category:BestOf. It did the substitution, but it's also changing quite a few zh-tw: interlanguage links to zh: for no good reason.

At https://desencyclopedie.org/w/index.php?title=Charles_Darwin&type=revision&diff=726263&oldid=701916 a link to [[zh-tw:大耳蚊]] becomes [[zh:大耳蚊]].

At https://desencyclopedie.org/w/index.php?title=Web_2.0&type=revision&diff=726687&oldid=571789 a link to [[zh-tw:Web 2.0]] becomes [[zh:Web 2.0]].

...and there are others. These tend to be pages which already have separate, existing links to same-topic articles on two separate wikis, zh: and zh-tw:

Maybe Wikipedia® treats zh and zh-tw as part of the same project, but Uncyclopedia® Taiwan is a different wiki with different users and different content from Uncyclopedia China (if the latter is even viewable at all, which is doubtful due to the Great Firewall of China). This is not a neutral substitution.

Is this a bug? Why is this occurring?