I would like Sketch Layer Notes to be more readily shareable to and from non-ArcGIS Online users. With Map Viewer Classic, I could grab a public Map Notes layer, save it, & bring it into ArcGIS Pro easily. From there I could export to another format as needed, and an exported KML would show names and notes associated with the mark-up.
To replicate the same process with Sketch Layers, it appears I have to open the whole map (can't find a way to share it as a feature layer) and then when I do open the map in ArcGIS Pro, exporting it to a KML does not preserve either the names or notes. So, unless I'm missing an alternative, I'm requesting a feature update to get that functionality back. Until then, we'll stick with Map Viewer Classic.