It's not like Gmail doesn't show "nudges" and other crap all over the place for stuff like this.
Besides, since in the proposed solution the system is creating the filter, it could bypass checks that require the label not be sent. Just because it shows in filters, and it can be removed from filters by the user, doesn't mean it has to be able to be created through the normal filter mechanism. You still have a "system of record", if that's how we want to refer to this feature, it just requires a single initial setup step on the first received email that is intended to be kept as sent. That's entirely in line with how Gmail currently does things, such as allowing alternate From addresses (which requires an authorization step).
(In fact, it's a bug that defeats the central purpose of the “system of record” feature it’s been suggested that the underlying functionality exists to support, as trustworthiness is the essential point of a system of record.)
¿Por qué no los dos? It's a feature to people with insane business requirements, and a bug for the average user.