I use to manage a hosting company and had several large companies using our hosting equipment, we used to daisy chain/cluster the servers. So if one server crashed the others would take the strain until the other server was rebooted. This way there would be no connectivity interruptions.
If several servers crashed we would shut the whole cluster down for 24 hours or until the connections died down (extremely rare). Apple haven't done this as iTunes, apps store etc are still online and those are linked to the updates section.
So my only guess is their not ready for the official release for some reason.