Horia,
   This is the only way I have found to get the features title based on the PopupTemplate.
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no">
  <title>Intro to PopupTemplate - 4.10</title>
  <style>
    html,
    body,
    #viewDiv {
      padding: 0;
      margin: 0;
      height: 100%;
      width: 100%;
    }
  </style>
  <link rel="stylesheet" href="https://js.arcgis.com/4.10/esri/css/main.css">
  <script src="https://js.arcgis.com/4.10/"></script>
  <script>
    require([
      "esri/Map",
      "esri/layers/FeatureLayer",
      "esri/views/MapView"
    ], function(
      Map,
      FeatureLayer,
      MapView
    ) {
      
      var map = new Map({
        basemap: "gray"
      });
      
      var view = new MapView({
        container: "viewDiv",
        map: map,
        center: [-73.950, 40.702],
        zoom: 11
      });
      
      var template = { 
        title: "Marriage in NY, Zip Code: {ZIP}",
        content: [{
          
          
          
          type: "fields",
          fieldInfos: [{
            fieldName: "MARRIEDRATE",
            label: "Married %",
            visible: true
          }, {
            fieldName: "MARRIED_CY",
            label: "People Married",
            visible: true,
            format: {
              digitSeparator: true,
              places: 0
            }
          }, {
            fieldName: "NEVMARR_CY",
            label: "People that Never Married",
            visible: true,
            format: {
              digitSeparator: true,
              places: 0
            }
          }, {
            fieldName: "DIVORCD_CY",
            label: "People Divorced",
            visible: true,
            format: {
              digitSeparator: true,
              places: 0
            }
          }]
        }]
      };
      
      
      var featureLayer = new FeatureLayer({
        url: "https://services.arcgis.com/V6ZHFr6zdgNZuVG0/ArcGIS/rest/services/NYCDemographics1/FeatureServer/0",
        outFields: ["*"],
        popupTemplate: template
      });
      map.add(featureLayer);
      featureLayer.when(function(){
        var query = featureLayer.createQuery();
        query.where = "OBJECTID_1 = 8";
        featureLayer.queryFeatures(query).then(function(results){
          var popupTemplate = results.features[0].getEffectivePopupTemplate();
          results.features[0].popupTemplate = popupTemplate;
          view.popup.features = results.features;
          setTimeout(function(){
            console.info(view.popup.title);
          }, 10);
        });
      });
    });
  </script>
</head>
<body>
  <div id="viewDiv"></div>
</body>
</html>