I would actually not go that far - I respect the devs enormously for having written the code and shared it with the entire world. If someone else wants to write new code - K/Mbin and Sublinks come to mind - then sure replace Lemmy for those instances that run that, but e.g. Lemmy.World is definitely a Lemmy and I'm okay with that.
I'm also okay with Fediverse - should I not be? I suppose an alternative is something that implements the ActivityPub protocol, but why not the Fediverse?
Basically I am okay with anything so long as people don't stumble upon it unawares.
But I do see your point that we can't just say that we are a Reddit knockoff, even though that's literally what we are. It should be the start of additional description. So far I call it "social media" - where people share and talk, bc that seems about right. "Link aggregator" doesn't do much for me, and suggests more of a purpose to read news stories rather than make our own posts.