It's quite possible that they have those, but that the credentials are stored in a tool hosted in that datacenter or that the DNS entries are managed by the DNS servers that are down right now.

You are probably right but if that is the case, it isn't really out of band and needs another look. I use OpenGear devices with cellular to access our core networking to multiple locations and we treat them as basically an entirely independent deployment, as if it is another company. DNS and credentials are stored in alternate systems that can be accessed regardless of the primary systems.

I'm sure the logistics of this become far more complicated as the organization scales but IMHO it is something that shouldn't be overlooked, exactly for outlier events like this. It pays dividends the first time it is really needed. If the accounts of ramenporn are correct, it would be paying very well right now.

Out of band access is a far more complicated version of not hosting your own status page, which they don't seem to get right either.