Bug 331582 binding context processing should be done in binding Contexts addon
org.eclipse.e4.ui.model.application.commands.MBindings.getBindingContexts() is currently processed in E4Workbench but should be done by the binding contexts model processing add on, and should add the event broker to listen to additions. PW
bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/workbench/swt/util/BindingProcessingAddon.java
.copy((EObject) binding);
							oldBinding.getParameters().add((MParameter) oldObj);
							updateBinding(oldBinding, false);
							updateBinding(binding, true);
						}
					}
				}
			}
		};
		broker.subscribe(UIEvents.buildTopic(
				UIEvents.BindingTableContainer.TOPIC,
				UIEvents.BindingTableContainer.BINDINGTABLES), additionHandler);
		broker.subscribe(UIEvents.buildTopic(UIEvents.BindingTable.TOPIC,
				UIEvents.BindingTable.BINDINGS), additionHandler);
		broker.subscribe(UIEvents.buildTopic(UIEvents.KeyBinding.TOPIC,
				UIEvents.KeyBinding.COMMAND), additionHandler);
		broker.subscribe(UIEvents.buildTopic(UIEvents.KeyBinding.TOPIC,
				UIEvents.KeyBinding.PARAMETERS), additionHandler);
		broker.subscribe(UIEvents.buildTopic(UIEvents.KeySequence.TOPIC,
				UIEvents.KeySequence.KEYSEQUENCE), additionHandler);
	}
	private void unregsiterModelListeners() {
		broker.unsubscribe(additionHandler);
		broker.unsubscribe(additionHandler);
		broker.unsubscribe(additionHandler);
		broker.unsubscribe(additionHandler);
		broker.unsubscribe(additionHandler);
	}
}