Words exist in a context. "User was banned from a site" and "Book is banned" have different connotations. You have to be purposely obtuse to conflate these.
just like how you can figure out when tom/dan say "we've banned this account" doesn't mean "banned this account from the internet", you can use similar context clues to figure out "banned book" doesn't mean "banned across the world and is now illegal".
I mean, when you're like "I have to make a hidden wifi server in a light bulb to distribute these books" that does kind of imply some dystopian totalitarian state that will put you to death for reading those books or something and not the reality that they are given their own highlighted section in literally every single bookstore in existence.
Did you read the article? The author doesn’t say anything like that.
It’s pretty clear this was mostly a fun idea with a bit of “could be useful in this scenario” motivation, which they mention came from reading a short story.