It's not a seperate universe, so much as a different lens through which to view the fediverse, and ny nature of being a different instance, it will also have it's own community.

If I could stick lemmy and kbin front ends on the same instance, and let people choose, I'd do that, but alas, it can't be done.

And personally, I prefer what kbin will be (though not what it is now) compared to lemmy. The tighter integration with the wider fediverse is a killer feature