Hi Steve -
I have looked again at the issues you face. As an aside, I think that potentially, the ArcGIS Online Assistant link that I sent may have been an earlier iteration of Geojobe's applications that do the same thing - not sure. It does still have the function of setting URLs to another URL. I am looking at it right now.
StoryMaps seem to present a different situation.
One thing is that StoryMaps start off in a different root than the rest of our AGOL content. It appears that if we try to move the StoryMaps we make off that root, to say our own site's root on AGOL - things break.
I can't look at a Portal right now to determine if StoryMaps in Portal come from the internal source our how that looks since it is inside a firewall vs. being outside the firewall. I suspect that all of these are situated in the storymaps folder up there - but, I'm not looking at the information architecture paths on this except through the browser's developer tools.
Of course when we are building dynamic content, the user-experience full life-cycle is often time not thought about in our fast-paced development scenarios - we find that often people just start developing maps and apps without any sort of overall design plan or thought about forward life-cycle of maintaining over a long period of time. It seems that the focus is more about quick delivery of the application and what the needs are for it - and sometimes the "hurry up" factor overrides all other aspects.
Migration paths often seem to be afterthoughts. At this point in my decades long career, I could write an entire book about GIS migrations and management of change! Yet here we are and we just do what it takes to keep our users' needs fulfilled, if we can.
A suggestion of on we might, for the future, is to put up in ArcGIS Ideas a request to make maintaining these StoryMaps more sustainable, by enabling content publishers/authors to utilize a custom URL (or rename a URL), as you would a web page or post as we are able to do with web content in other platforms.
I'm not the expert on this - but, through maintaining several websites that use different platforms, most have this capability.
But, one simple idea might be to request the ability to customize our URLs so that they make more sense to our end users and we can manage moving to the newest versions with less headaches and impact to them, so that they can continue receiving good uninterrupted service from their apps. Any change we can reduce is of benefit to them in doing their daily work, which often does not involve managing IT stuff.
