Domains re-added. They should work within 2 hours.
And yeah, I agree that messaging can be confusing especially for users with external DNS who may not realize the domain needs to be added. The page was written with the expectation that users would be using our DNS (which back in our cPanel days was actually a requirement to add the domain). For users who do use our DNS, an unconfigured domain simply doesn't resolve and returns NXDOMAIN instead of that page, so its obvious its not set up. When external DNS is used, it's possible to force an unconfigured domain to resolve, and the server just shows that page because it has no idea what to do with requests for the domain.