[standalone@localhost:9999 /] cd subsystem=datasources/data-source=ExampleDS/statistics=pool
JBAS014808: Child resource '"statistics" => "pool"' not found

Same for the statistics=jdbc resource.

The JMX mbean exposing the datasource resource is broken for this as well.

Interestingly, navigating to the parent, and then doing

:read-resource(include-runtime=true, recursive=true)

shows the resource information. The CLI GUI must work this way, as it shows the resources.