https://vacationtracker.io/wp-content/uploads/2019/04/hexago...
This seems like a new buzzword for an existing (but still very good) thing, abstraction layers.
The original article (http://alistair.cockburn.us/Hexagonal+architecture) is down though, so it's entirely possible it was was written in the late 90s when these practices started becoming widespread particularly with Java and Gang of Four (https://en.wikipedia.org/wiki/Design_Patterns).
Edit: dzone says 'Hexagonal Architecture' was from 2005. https://dzone.com/articles/hexagonal-architecture-what-is-it... Make of that what you will.