After unjoining and rejoining the domain the AIX RBAC roles are removed and need to be added back manually.
原因
Unjoining the domain removes the users attached to the domain and thus the roles are removed as well.
解决办法
This is expected behavior of Authentication Services. When a host is unjoined from the domain the users are removed and thus the roles assigned to those users are removed as well.
When rejoining the domain the roles will need to be re-assigned manually.