Interesting that in the title, stated in absolute terms in the text, and from the designers they interviewed, they cite getting lost as crucial for the genre. Personally, I disagree. Getting lost has tended to be why I didn’t care for certain games in this genre, like Axiom Verge, and it soured my otherwise higher opinion of games like Hollow Knight and Symphony of the Night. Still, I think this is a good exploration of the genre and what makes it tick.
But that’s exactly why we have the word metroidvania.
It was sometimes used derisively in forums, but it was to tell apart the likes of Symphony of the Night from the likes of the linear ones. And then as we got more Castlevanias like Symphony of the Night in the GBA era, it became part of the definition of what this genre is.