Lets clarify Terminology a bit
Watcher is the legacy / code only alerting and notification framework (which I think you are not referring to... perhaps you are)
Kibana Alerting is the new framework which I think we are discussing, and yes there is a feature request / issue... you can find it here. (I had it opened as a result of our conversation) of course there are many items in the backlog so I can not speak to its priority or schedule. I do know that the DSL search for Kibana Alerting is a pretty high priority.