Can we instantiate COM object in plugin

I read this statement in 1 of the Adobe DC SDK guidelines -

"OLE or ActiveX server plug-ins must be implemented using the ActiveX Template Library." 

Could anyone please clarify if it means that we cannot instantiate COM object for a COM server other than ATL (C++). We are instantiating COM object of C# generated tlb in plugin code and are facing issue when protected mode is ON.

Thanks