I think this ending, this last passage, is probably the closest we'll ever get to knowing exactly what happened to Julian he leaves.
SPOILERS AHEAD IF YOU'RE IN THE MIDDLE OF READING OR YOU'RE WAITING TO READ IT YOURSELF!!
I just really have to talk about this!
It took me at least three reads to register that it was not from Paul's perspective but from Julian's, because the entirety of the collection up until that point was from Paul's perspective.
It's from 2020, the same year that the book was published so my best guess is that it very nearly made it into the book, as the ending or maybe as like an epilogue but either Nemerever determined it would be confusing to jump perspectives or decided we were better off leaving it with Paul instead.
What happens is that Julian runs off to New York to stay with Joy, finds himself in a modern art museum, staring at a painting for nearly an hour. When he starts off the chapter, he's bruised and streaked with dirt so by the time he gets there, it's probably not long since what happened with Paul.
The rest of the excerpt is him slipping on a mask, figuring out a lie to tell Joy. He fixes his appearance and he tries to make himself believe that Paul killed himself anyway, with or without him. He doesn't picture him doing it by jumping into the ravine, but instead hanging himself after burning all his paintings. The line where Julian says to Paul "I always worry you're going to kill yourself" is kind of referenced because in his cover story of what happened, he says (or would be saying) "I always knew he was going to kill himself."
So the real truth is, based off this, is that neither one knows what happens to the other after they part ways for the last time, and it's so depressing oh my god. I ruined my morning with this, it's 8AM!
There's definitely a lot of useable material from violent ends that I will be using when I finally get around to writing my queer little essays. Mostly for Paul but this passage combined with what I've already gathered about Julian, gives me a lot to think about.