That is different level of abstraction and NTFS-only thing.
The mechanism mentioned in the article is Shell Namespace. Explorer.exe and friends do not operate on file system (ie. files and directories) but on tree of COM objects (called folders and items) that can represent pretty much anything, although usually represent file system directories and folders. The "Classes root" in "HKCR" means that this registry hive describes how names of these objects are transformed into the COM instances (either by directly naming the CLSID or by parametrizing the behavior of default class of filesystem objects). It works this way to this day. And for example the "Windows 10 God mode menu" is nothing else than exposing internal shell folder.
The mechanism mentioned in the article is Shell Namespace. Explorer.exe and friends do not operate on file system (ie. files and directories) but on tree of COM objects (called folders and items) that can represent pretty much anything, although usually represent file system directories and folders. The "Classes root" in "HKCR" means that this registry hive describes how names of these objects are transformed into the COM instances (either by directly naming the CLSID or by parametrizing the behavior of default class of filesystem objects). It works this way to this day. And for example the "Windows 10 God mode menu" is nothing else than exposing internal shell folder.