In the UK, it's noticeable that it's not just standard AppleCare you're adding, as the description changes to something like "APPLECARE HE UPLIFT" or some such.
From what I remember, with no uplift, the service and support page shows just the standard 1-year warranty to begin with, but then a month or so (maybe longer) after purchase, you get an email, and the AppleCare is added, and reflects in the service and support page.
Weird that the US is different.