I guess it depends
I guess it depends on what you mean by security, and the press release<<<<<<<<article doesn't really say. Yes an authentication layer can be added on top of WinNT, or a layer which claims to provide access controls, or a layer which claims to provide an audit log. And you can do these in an OS-independent way; indeed, stuff like CDSA aka Common Distributed Security Architecture has been doing much of this for some real OSes for a decade or more, but you almost certainly won't have heard of it (and it doesn't claim to be ready for niches like DO-178).
But as soon as anyone claims they put "a security layer" on top of Windows, it loses all credibility as a means of actually enforcing security in a meaningful way, because of the insecurity of the underlying OS.