Any downtime in a cloud service is an outage. Any attempt to term it anything else labels the organization as amateur.

The page reads maintenance. But it is a service interruption, wether planned or not, it is also an outage.

Without any kind of email or notice to developers, it's an outage. A big one.

I'm told this was scheduled.

It's hard to believe that something this long would have been scheduled but that they wouldn't have told anyone about it.