The Sketch docs for 4.10 list 'create' 'redo' 'undo' and 'update' as the events it can fire.
(Sketch | API Reference | ArcGIS API for JavaScript 4.10 )
There's a trash-can icon that fires a 'update:cancelled' event - but that's the same event as hitting escape during an edit.
But ... in the javascript source, an undocumented 'reset' event is fired when the user deletes via the trash-icon.
Is this simply missing from the docs, or a purposefully not-ready-for-consumption API?
(I'd like to listen to this event, and not worry about regression later on...)