What do they want with NLRB days in the first place? Maybe they have an idea; maybe not. The goal is "we got your data, be worried". Getting caught furthers that.
The use of the nlrb data on the other hand is pretty clear. They had a number of ongoing cases against Musk's companies. Involving Russia is unnecessary to explain the motive.
There are literally dozens of ways to kill a guy, if you must poison him, which are cheaper in every possible way and can be sourced locally by someone with the sort of basic chemistry knowledge an intelligence agency would have on payroll, or from a drunk undergrad.
Which is to say: Russia's MO has at no point been "subtlety", it's been vranyo: a lie they tell where you know they're lying, but are obliged to pretend the other party is not.