Not directly, but there's probably a workaround. Your existing method with Revit wouldn't work on a cross-platform application like Archicad (Revit is locked into Windows).
I can think of several possibilities:
1) Write a stand-alone .Net-based tool that you invoke from your add-on, passing whatever parameters are required to upload the target project
2) I think the deprecated RPC API for Sharepoint could potentially be called from an add-on - see
https://msdn.microsoft.com/library/4aa5c82b-90fb-4be5-b30c-d35ecae42a81%28Office.15%29.aspx
3) You might be able to leverage one of the other APIs, e.g. Javascript, indirectly (similar to point 1, but you might not need a full application).
Ralph Wessel BArch
Software Engineer Speckle Systems