Hey Katie Gaut,
Just saw your post while browsing the Geonet posts.
Idea- Create multiple ArcGIS Story Maps and embed each in a Cascade Story Map section (with section bookmarks on). Alternatively add the separate ArcGIS Story Maps to a Story Map Series' tabbed sections.
I know these aren't ideal solutions but might be a plausible workaround until the story map team adds bookmarked sections to the new ArcGIS Story Maps.