I assume it's nothing more than the notification process not working right due to some network issue. That's why they come through sometimes, but not others.
The 3-4 day market is not just a bunch of first time cruisers. There are plenty of regular and seasoned cruisers just taking the long weekend approach to vacations.
Also be sure (if you want it ) to specify your amenity item to the C&A person while asking about the status change.
Also, while your on card benefits will be updated for the next leg, your in room perks like amenity item or bottled water perk may not appear. Just ask, and they'll get it for you.