If its in SciHub, it's in Archive.org, just not accessible.
Say more? All of scihub is mirrored at archive.org? Where do I find out more about this?
You don't. shhhh
How do we know it's actually a thing at all, and not just something someone made up?
It's not quite a secret, you can see yourself if you look closely enough.
We found that in some cases, some of the published articles are archived through the Internet Archive! (Yay!) Unfortunately, this doesn't amount to complete issues/volumes and seems to be by chance.