If you look at where the content on https://status.aws.amazon.com/ is actually hosted from you'll see things like the status icons are all hosted under the same domain, e.g. https://status.aws.amazon.com/images/status1.gif https://status.aws.amazon.com/images/status0.gif etc.
If you look at the source code for the site, you'll again see that everything is hosted from the same domain.
One of their main goals was to ensure that it could never go wrong that way again.