Actually, they should have had staffers CALLING their customers, especially those paying for larger accounts and/or dedicated
The flip side to that argument is the staffers should be working to restore service faster instead of wasting their time on the phone.
As long as someone posts a message on their web site and changes the voice mail message to let me know they are aware the servers are down and working on them, I'd prefer all hands working to restore service instead of answering the phone.
In reality, customers with down servers, especially when it's known to be a larger issue, are often their own worse enemy during a crisis.
When you're demanding to waste the time of the staffers by whining on the phone instead of letting the staffers work to restore their service, you've become part of the problem, and people just don't get it.