Currently with classes in ArcGis Pro SDK, you can only display points, lines, and polygons on the fly using the "MapView.Active.AddOverlay" function, but you can not display text.
Example to display a point on the fly:
symbol = Await QueuedTask.Run(Function() SymbolFactory.Instance.ConstructPointSymbol(ColorFactory.Instance.RedRGB, 5, SimpleMarkerStyle.Square))
_PointOverlay = Await QueuedTask.Run(Function() activeMapView.AddOverlay(point, symbol.MakeSymbolReference()))
