[allturtles]

> A fact-book, that lists the current heads-of-state of all world nations, then possibly yes.

If you want to sell an up-to-date, 2024 factbook, you should commission one. Providing up-to-date fact books is not a function that a back catalog can or should serve. You shouldn't take a 1950s fact book and try to make some ham-handed edits to it and sell it as if it's the same book.

> if a book says something dangerous - like a cook-book saying "add a few flakes of cyanide for flavour" is that grounds for an update, or editors note in an otherwise historical record text?

If a publisher feels that issuing a particular book in ebook form would be injurious to the public, than they are certainly within their rights to not issue it. Or to add an editorial note "This book is for historical interest only, don't try to use the recipes, because for some reason the author was trying to kill all their readers." Again there are a zillion cookbooks and it's not hard to get someone to write a new one.