A very basic feature such as copying a shape is missing in the PowerPoint APIs. The closes we get (in my understanding) is the general Office API getSelectedDataAsync(Office.CoercionType.XmlSvg). First of all this seems not to work and I have reported this (https://github.com/OfficeDev/office-js/issues/3309) and you have added it to your backlog with bug ID 7823481. Even if it would work as expected it would still only give us the svg vector for the shape and not the adjustment points and other specifics that would be the case for a true copy shape API.