openshift-install is always raise WANING when install a cluster on AWS Region us-east-1 with default configuration, no zones is set.

~~~
WARNING failed to find default instance type for worker pool: no instance type found for the zone constraint 
WARNING failed to find default instance type: no instance type found for the zone constraint 
~~~

The process to discover zones list all zones in the region, then tries to describe instance type offerings across all zones from a list of supported instance types by installer.

The problem that there is an "dead" zone in this region, the us-east-1e (ID use1-az3), which does not support any instance type we support, leading in creating infra resources in one zone which isn't useful as may not able to launch supported instance types there.

* (?)    

always    

    1. create install-config targeting AWS region us-east-1, without setting zones (default)
    2. create manifests, or create cluster
  
    

~~~
WARNING failed to find default instance type for worker pool: no instance type found for the zone constraint  WARNING failed to find default instance type: no instance type found for the zone constraint 
~~~

The WARNING is raised, the install does not fail because the fallback instance type is supported across zones used to make Control Plane and Worker nodes

No WARNINGS/failures