Does the black hole recently discovered that is the closest to Earth have any importance concerning our problem with extraterrestrial interlopers?

Although you are pessimistic about this potential link, we can tell you this is absolutely a critical component and is an active way in which extraterrestrials accomplish their interstellar travels. The black holes are a gateway that can be used in time travel very, very expeditiously. They are not essential for this but there are particular advantages in using their energy. The extraterrestrials have mastered this science and use it to great advantage. This is how they are able to go throughout various star systems and accomplish a great deal personally despite the enormous distances involved. So having a black hole in your proximity increases the likelihood you will be visited by members of the Extraterrestrial Alliance, at least within the Milky Way Galaxy, and therefore represents a risk factor.