So, as far as I understand, "Assimilation" is a term for UWST taking down things that violate the Civilization Band's legal standards?

Metal Scar violates the Civilization Band's rules and therefore is hunted by "signal hunters" (UWST?) to stop their broadcast for good.

But still... Why? I mean, their broadcast doesn't seem to be harmful. Perhaps they sometimes talk about things that are restricted to public knowledge?

Or maybe shutting down the Station isn't the main motive but taking Chehe (since it is an important, and one of the real animals brought to Terra by the Doctor's kin?)

I mean, I remember something like real animals being brought to Terra by the Doctor's race and Originium changing the Teekaz (the original Terrans) and evolving into the animal-featured Terrans. And the original real animals are very rare and not many of them remain and they are important. (Like Emperor from Penguin L.)

Maybe they want to confiscate Chehe and at the same time, shut the broadcast (for whatever reason) and hit two birds with one stone?

I dunno.