According to Azure documentation, https://msdn.microsoft.com/en-us/library/azure/dn439773.aspx, Active Data Guard or Golden Gate are options for achieving high availability when running Oracle databases in Azure.
The cited benefits of ADG (reporting, backup offloading) are not priorities for our application. Will Oracle Data Guard do just as well for HA?
Oracle Active Data Guard is a licensed option introduced in version 11g. With Oracle Data Guard, you will have the same functionality in terms high availability. Switchover and failover will work the same way.
So the answer is yes.