I get where you’re coming from: a common terminology will help make kbin and lemmy more accessible to each other’s users and to the wider world.
That being said, I think it’s fine to have separate terms (communities vs magazines) as long as the platform (lemmy, kbin, etc) calls it that consistently and it gets adopted into the common language of the platform.
I also think that having different terms for each platform emphasizes how connected the fediverse is! This would point to a larger discussion of how seamless federation should be, but I think it’s good for each platform to have its own identity under the fediverse.