I don't think Homestuck is nearly as niche as you think it is. You realize in its heyday the kickstarter set the record for highest amount raised? Like. It's not anywhere near as popular right NOW but it's also a concluded work and since it concluded it's basically become 'cringe' to be something you're interested in to the wider internet, largely due to a combination of the stupid discourse that used to come out of the internet.

Regardless though there's several larger shows that attribute at least a portion of inspiration to Homestuck, I mean it's literally shouted out in Steven Universe alongside like FF7, the person who made the locked tomb mentioned Homestuck as inspiration, hell there's a homestuck reference in fuckin bluey of all things.

I personally think this is going to at worst, leave the fandom exactly how it is now, and at best will make people actually want to read the comic afterwards.