Genre classifications are mostly irrelevant to me. Whether or not someone would classify a book as “hopepunk” is entirely irrelevant to my decision to read it.
And this notion that there is no “hopepunk” canon of recognizable literature seems like a straw man argument to me. Perhaps the canon is still forming. Perhaps it will never form. Does it matter? Does that change whether or not you will read a book?
The term isn’t great. The “punk” suffix is way overused in literature. And “hope” is way too broad. I once heard “hopepunk” used in reference to a bleak horror story. That being said, once words are introduced into language we lose control over how they are used.
If I say something is “hopepunk” and you say, “No, it’s not because the person who coined the term says it’s not.” I’ll say, “Who cares? The word is being used differently now.”
This so-called “manifesto” is not and will not be the last anyone has to say about “hopepunk”, and to say it has to conform to their definition of it seems to misunderstand how language evolves and meaning changes over time. They do not own “hopepunk” any more than you or I do.