On plwiki there are some orphaned entries in table categorylinks. Category is empty and these pages are not in this category anymore. Probably it is releated with page moving, redirects, tagging redirects for deletion, moving over redirects.
So I can confirm this has the same results in production, so consistency across labs and production is the same, which was my initial concern.
Not sure what is the fix for this, but I am not sure we DBAs can act on it, as it seems more wiki related.
Can you give more details on what needs to be done?
Entries about these pages (linked in categorylinks) should not exists because these pages were removed from this category. So MediaWiki code for categorylinks update not always working after decategorisation.