If you want a recipient controlled option that already exists as you can set the number of messages you want to save before old ones are deleted. Not deleting

If you want a recipient controlled option that already exists as you can set the number of messages you want to save before old ones are deleted. Not deleting the messages from the senders view just to teach users a lesson about security doesn't make any sense and would just confuse people. Showing a warning about it still being possible to take a picture of the phone with another camera would make more sense but seems a bit silly.