As far as I know the only solution is to create a series of ICML files with boilerplate text and if you want graphics, to anchor them in the text and embed them in the file (not linked). You can place the same story in multiple ID files but they have to remain in their own text frame in order to maintain their link to the "source" ICML file. So you can't link just a single paragraph from a story, for example.
In any placed instance you'll see the Available icon on the story frame, whether you're looking at it in an INDD file (in InCopy or InDesign) or an ICMA file (in InCopy). As soon as anyone checks out any instance and updates it, it forces all other instances to show an out-of-date icon, so you have to be careful. If you don't want your changes to affect other placed instances, the user has to Unlink the story before making changes. Only the InDesign user can unlink linked InCopy stories, from their Assignments panel or their Links panel.
You can get close to the same functionality with CC 2018 libraries in InDesign, because you can now use them as the source for text snippets. But InCopy doesn't have a CC Libraries panel.
AM