rMW522dcec59c7a01e53eb14bd22b9906378d13685f changed the English noindex-category from "Noindexed pages" to "Non-indexed pages".
It's the name of a tracking category many wikis have created at the old name which has been a MediaWiki default for several years. There is no compelling reason for the change so it should be reverted to "Noindexed pages". (Change "noindex-category": "Non-indexed pages" back to "noindex-category": "Nonindexed pages" in languages/i18n/en.json.)
Discussed at https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(technical)#Category:Non-indexed_pages where the author of the change said "Open a phab task and ill fix in the morning".