We recently introduced a new event primitive that allows you to send events to CommandBar, and then have CommandBar react to those events. While metadata is useful for passing values, events are ideal for situations where the user took some action or where there is a change in your app.
For example, you could push an event to CommandBar when the user does something like publishes a new article. Then, using those events, CommandBar can react and push out a nudge, etc. Additionally, you can have CommandBar only react when a certain number of events have occurred — for example, when the user has published three articles, you might want to suggest that they organize their articles into folders.