Esme Povirk (@madewokherd) commented about dlls/uiautomationcore/uia_classes.idl:
interface IWineUiaNode : IUnknown { HRESULT get_provider([out, retval]IWineUiaProvider **out_prov);
HRESULT get_prop_val([in]const GUID *prop_guid, [out, retval]VARIANT *ret_val);
This seems to be unused in the patch that introduces it?