Seems pretty normal to me. Your first sentence is taken from the abstract, a short summary of the article as a whole, so details are excluded or glossed over. Your second sentence is from a section titled "Actor", which goes into actual detail on who the actors were and so has more fluff like this. They go on to explain their reasoning in that section -- you can't actually create an account from Russia itself, but a VPN can be used to bypass the block, which lends some uncertainty. They then proceed to systematically eliminate that uncertainty by showing how the accounts were acting.