Is it possible to redirect an existing Story Map App map to a new map within my Organization on ArcGIS Online? I did a "save as" on the original web map that the Story Map was based off of, edited the original map for other purposes, and now lost my map tour layer (though it exists on my new "saved as" map). I'd like to point the Story Map App to my new map.
No sorry there is no user interface that let you do that in Map Tour.
You will need to recreate a Map Tour from your new webmap, so you will have new application id that will be different from your older MapTour.
Note that this is technically doable for developers that knows how to modify the item data to point to the new webmap but I don't know any tool that let you do that easily.