"Why do we lie to children in the places and times we do" is its own fascinating topic, but are we expecting anyone encountering Charlie and the Chocolate Factory for the first time to be reading it through a lens of "how things were in the past" lens?
I'm not sure. Bright children might indeed notice some things and ask questions about them. My childrens' first encounter with Matilda was via me reading it to them, at the ready for any questions they might have had, and also (great nerd that I am) probably trying to provoke questions and answer ones that were never asked.
