Can these time-enabled maps and stories be created only by writing code? https://www.esri.com/arcgis-blog/products/arcgis-storymaps/mapping/storytelling-with-tracks. We may not have time for learning it so it may not be the most efficient way to accomplish what we need. We want to show the many pathways nitrogen pollution travels through the Mississippi watershed from upstream to downstream where it dumps into the Gulf. We have ability to create generic animations, video clips, gifs, etc. But I think this tracking tool would have a more realistic feel and add more impact in our story.
Hello, the blog you've linked to demonstrates a specific functionality of the ArcGIS Maps SDK for JavaScript that can only be created by authoring code. However, there are many ways to visualize data and incorporate time as a variable. This blog on Showing time in ArcGIS StoryMaps describes a number of methods that could be employed to show differences or changes in a dataset over time.
I would recommend starting there and then possibly exploring whether you could use a timestamp attribute within your data to animate the data with the available time properties Map Viewer.
Warren