I found it, for some reason
getDrawFeatureOptions().onFeatureAdded
doesn't do the trick, I had to inject the listener in GWT using:
getWidget().getDrawFeaturePoint().eventListeners.addListener(getWidget().getDrawFeaturePoint(), featurePointAddedlistener, EventType.VECTOR_FEATURE_ADDED, new EventHandler() {
@Override
public void onHandle(EventObject eventObject) {
FeatureAddedEvent e = new FeatureAddedEvent(eventObject);
featurePointAddedlistener.onFeatureAdded(e);
}
});