Those are referred to as "orphan" web pages or dead end pages as they are not linked to the site and not linked from anywhere. They have been around and discussed on this board a few times over the last couple of years. Every time someone discovers them they think they have discovered KMAG's return to the web. They haven't.
Those pages never left (hence they never had to be "reactivated")...and where probably being used by the developer when the website was changed many many years ago and never taken down.