After hearing back from Microsoft support (and by proxy, the Visual Studio development team), it is clear that this issue is very low priority for them (they see it as having trivial business impact), so we cannot expect it to be fixed in the upstream libraries anytime soon.

This response essentially means that if Python wants to support these symbolically-linked directories, it cannot use stat/wstat on Windows and must use instead the Windows APIs.

As seen in issue13412, this bug not only affects import.c, but also affects posixmodule (such as with os.listdir). After addressing this issue for import.c, it will probably be necessary to also address it for other parts of Python that use stat/wstat (or other calls that depend on those calls).