Well, the Russians love making nuclear threats all the time so maybe it’s good to remind them that it can be THEIR cities that get atomized, too.
This particular hack appears to be rather amateurish, meaning it was probably done by a teenage Russian out to have some fun to see what he could get away with.
Meanwhile, Avdivka is a developing encirclement, another cauldron in the making? Expect more with the fall of Artyomovsk ( Russian name for Bakmut).
https://www.youtube.com/watch?v=bZEAiVo2MNg