"The Fanontinuum" is actually a legacy concept from the original HS^2 outline, which can still be found on a web archive of the Homestuck Patreon:

"No longer must our heroes toil in the service of the "alpha timeline." The Prince and his Seers seek to preserve the Canon-That-Was at great personal and narrative cost. But inside the black hole, those who the paradox once discarded seek to claw back to relevance and escape to the Fanontinuum, a new fabric of story and space woven by the hands of new narrators, thousands of voices that fill the vacuum left by the death of the author."

I don't think the new version of the idea will play out exactly as described here, but I've come to suspect something similar; the Candy version of planet Earth is basically done with its story, now, and though some characters might eventually escape to chase after Dirk on Deltritus, it seems unlikely - and counter to many of their character arcs - that all of them will. So my guess is that, throughout the story's future Intermissions, we'll continue to see characters from that world fall through the cracks and end up in the Fanontinuum as Crowbar did, bringing some finality to their stories while still preserving them in a way that both keeps the fans interested and is respectful of the message the story is trying to tell.

Beyond that, the Paradox Space stylings of the first Intermission make me think future installments will follow suit and show us these characters in new styles, through the eyes of new writers and artists, in a similar way to what was originally promised.