Not quite, COM yes, although it is masochistic to do so without any higher level help.
UWP on the other hand extends COM to support inheritance and value types across calls, and the lowest Microsoft was willing to go on their high performance components was the Windows Runtime C++ Template Library, now replaced by C++/WinRT bindings and updated MIDL compiler.
The ABI is still C. Value types are just structs, and inheritance is implemented via aggregation - under the hood, it's all just interfaces and conventions on how they all play together. So any language that can do C FFI, can do WinRT. We did most of it with Python and ctypes as a prototype.
And you could even use that from C back in the day if you #included the "Windows.*.h" headers that shipped with the SDK - they had a bunch of #ifdef __cplusplus etc in them. Not sure if that stuff is still there or not.
UWP on the other hand extends COM to support inheritance and value types across calls, and the lowest Microsoft was willing to go on their high performance components was the Windows Runtime C++ Template Library, now replaced by C++/WinRT bindings and updated MIDL compiler.