This is user error, need to add in mapOptions when creating the Map, see this snippet,
var createMapOptions = {
mapOptions: {
showLabels: true
}
};
//if accessing webmap from a portal outside of ArcGIS Online, uncomment and replace path with portal URL
//arcgisUtils.arcgisUrl = "https://pathto/portal/sharing/content/items";
arcgisUtils.createMap("aea3672f86ba41fa8c205997b5f5cb98", "map", createMapOptions).then(function (response) {