No. Hardlinks and CoW filesystems are different things.
I don't know much about hardlinks on windows, but hardlinks usually are two different inodes pointing to the same file. This means, for the user, a single file appears duplicated, but without using any extra space. However, both files are really the same one, so if you modify one, the other one also gets modified.
CoW filesystems, on the other hand, are a bit more complex. When you store a file, its contents get first stored, and then a file references them. When you copy the file, a copy of the reference is made, and there is no need to copy the content, because it's already there. If you modify one of the copies, the difference between them gets stored (the modified content), but other parts of the file (or files in a folder) that don't get modified are not duplicated.
Tell me you don't know what you're talking about without telling me you don't know what you're talking about.