Regarding coupling, I don’t disagree. But I don’t write the systems, either.

Some marketing services allow for content buildout and then you create the query that pulls a list based on multiple factors. It then marks the recipients as being included on the list for the campaign. The same content can/will be used multiple times for different people, so tracking what emails are sent to whom and when is vitally important to track marketing qualified lead scores. This metadata is handled by the systems - not manually updated initially. Revising any of this is not worth it for the few unsubscribes you MAY possibly have.

As mentioned in another comment that I wrote, smart lists eliminate most of this hassle. You can use them to schedule an email and the email then goes out with a more recent (near-current) list. There are still some unsubscribes that this might not catch (such as when there are other systems integrated, like salesforce, and the two systems don’t speak well together) so you still need the disclaimer.

Regarding the x day deadline, it is rare when emails are scheduled longer than a week out. Some could be, but the strategy might change, some content might be swapped out, or you may decide to kill a campaign. Just as it is not best practice to overly critique a pulled list, it is also best practice to not schedule too far out so you don’t end up spinning wheels for naught.