Your issue looks related to : https://issues.jboss.org/browse/HAL-750
This issue is fixed in HAL 2.8.11 which is used by WildFly 10
Please try WildFly 10 you should be able to see it in console. In WildFly 10 you can see those settings in : http://localhost:9990/console/App.html#profile/deployment-scanner By default the deployment scanner is enabled so hot deployment can be done with default configuration.
OK thanks Jay!!!
Deployment scanner was removed in WildFly 9 but hot deployment is set by default.
Just wanted to add ... the "deployment-scanner" configuration page/option was missing from admin console. However you still have the CLI ($JBOSS_HOME/bin/jboss-cli.sh) option to enable or disable the deployment-scanner as following: