It's rather meaningless to let the receiver decide. It means that the only safe-not-to-be-rude option is to adhere to the strictest interpretation of rudeness. At the extreme sensitivity, you basically can't communicate with anyone unless you ask their preferences beforehand over a confirmed-not-rude channel.
Following this direction puts the default for each medium, regardless of its properties, into "it's rude to attempt communication".
IMO, it's overkill. We invented communication to communicate, and we built in things like being asynchronous to some forms of communication. So we should not give them up just because someone might find it rude. There's a level after which the sender should have more say over what is rude than the receiver.