Yes, and also for many managed services (like Kinesis or Lambda) you don't have any control over which AZs are in use, and so you have no choice but to wait for

Yes, and also for many managed services (like Kinesis or Lambda) you don't have any control over which AZs are in use, and so you have no choice but to wait for the AWS teams to address any problems caused on their own backends. Regardless, it's important to be aware of the risks of whatever tool you're using. It's unrealistic to expect any provider to be able to avoid failure entirely. You have to be aware of possible failure scenarios and have your own plan to address them.