Unfocused Event Not Firing on User Control

I created a simple Xamarin Forms user control based on a ContentView. Since the ContentView is (ultimately) a VisualElement, I assumed the built-in Unfocused event would work as expected. However, while I can subscribe to my user control's Unfocused event, the event never fires. The Xamarin documentation for the Xamarin.Forms.VisualElement.Unfocused event is cryptic:

 This event is not bubbled through the Forms stack and is received directly from the native control.

Is this suggesting that I need to implement the Unfocused event explicitly within my user control?