This feels like it should ideally be something public in the structs package so anyone can leverage it, not just a specially blessed internal thing for the sync package.
You can exploit the mechanism described in the article yourself, but it's already changed once in the past and is not part of any compatibility guarantee. As with structs.HostLayout, a blessed structs.NoCopy in the standard library could guarantee that it works forever. I think the bigger issue remains that it doesn't actually do anything in the language (but, then again, neither does structs.HostLayout--yet).
I agree, its a nice piece of semantics to be added to a struct