in ArcMap is possibile to insert Office object such as a Word document, an Excel sheet, a PowerPoint slide; the objetc is "linked", so that any change to the slide, for example, will be reflected in the layout. In Pro this is not supported, and is not in plan(see https://community.esri.com/message/774209-re-import-of-objects-word-documents-pdf-in-arcgis-pro-layo... ). This is a powerful functionality that can enrich a map and especially a layout with additional information that is updated by non-GIS people.