When there are global user pages (T16759 ?), some user lets delete their local userpages.
But there is now problem, if bot's page or talk page was redirect to local user page - now is listed on [[special:brokenredirects]]

see eg. https://sk.wiktionary.org/wiki/Diskusia_s_redaktorom:JackBot which is redirect to https://sk.wiktionary.org/w/index.php?title=Redaktor:JackPotte
but this page does not really exists on sk.wiktionary.