With changes in 2.15 the name of the alertmanager accessor and route secrets is changed to include a suffix to identify the hub cluster.  

That suffix is included in the hub-info secret, however with MCOA enabled the hub-info secret is not created.  This makes it difficult to configure alertmanger on the managed clusters.

Adding labels to these secrets would simplify identifying them in policies and would be less likely to break customer environments in the future if the name is changed for the fourth time.