It used to be Metamodernity, but for a couple of reasons, we decided to change the name:
The prefix poly means several, whereas meta means beyond, and polymodernity is about bringing several cultural codes together, so polymodernity makes more sense than metamodernity.
There is also a concept named metamodernism, which is not the same as what I called metamodernity, but the two were constantly confused.
So, polymodernity it is!
And you can find the book and more about it here: https://www.nordicbildung.org/polymodernity/
The book Metamodernity first came out in June 2019, you can get the new version from mid-November 2023.