I don't think the distinction between holography and string theory is as clean as you're making it. The vague idea of holography predates string theory, but most of the working examples we have of holography come from string theory. That's what AdS/CFT is: It's an explicitly holographic description of superstring theory in an anti-Desitter space. It's frankly bizarre that the author of this article doesn't mention that fact. I suspect we are seeing a popular science rebranding of string theory without the word strings.

I didn't intend to assert a clean distinction, you're exactly right about its connection to string theory. What I mean is that String Theory Writ Large enjoyed a lot of popular esteem in the 00s and 2010s in public communication as being our potential new framework for what lies beneath the quantum world, but string theory is huge in and of itself.

It's more a difference of emphasis (holography in particular) than something that's outside the scope of string theory.