That may be a little too verbose and specific to that one setting to be able to make that change smoothly. It may be worth opening a ux topic to discuss how we can make those ‘apply default historically’ style messages more clear that they only apply to the default values.
I think this is a valid feature request. I’ve had a quick search for previous and found this one Send only system emails when disable email setting is on, though I’m afraid it received a pretty coolish reception at the time (there may be others though as that one is a few years old). Personally, I see the merit in such an option.