Hm... My view is that while the author inserts have only previously been relevant for foreshadowing or otherwise setting up callbacks, the way this one's being tied into the story is a bit different. I don't think we are specifically supposed to care about these characters (other than Spades), but they're filling roles as archetypes that have been created by other comics (perhaps the best-known author-insert storyline in a webcomic would be Bob and George). Given that, the difference is that Hussie's poking fun at the tendency for wish-fulfillment and similar ways of handling it by having his character have stereotypical Author-based superpowers and living in a similarly stereotypical "paradise" home (at the very least, it's quite a large estate, it seems), and then having all of that be entirely tangential to the part where he still dies. Which is also entirely tangential to the real plot.
Similarly, the end-of-intermission flash plays off fandom memes about him marrying Vriska, and having her seem pretty uninterested in the idea.
Of course, you're still entirely right. Neither of these jokes are based on anything in the actual comic, and that's a big problem for people who aren't familiar with author-insert shenanigans in webcomics at large, or with the community jokes, respectively. Especially that last one, which will render the joke entirely lost on archive-readers, kind of like how I didn't get the Hero Mode Gamzee joke until well after I caught up. It's also problematic for people who aren't reading Homestuck for the Hussie-related shenanigans, which renders this whole chunk of the intermission a fairly cliche "Look how badass the villain is!" moment at best, since there's no interest in the deconstruction.