I think this is way overblown.
If I remember correctly after the crash of the soviet regime all these labs were full of excellent scientists that were not getting paid and the labs could not be maintained. The US stepped in for a couple of reasons. One have these folks work for us and two, get the research that they were working on. So we kept paying them and the Russians government was pissed we took all the research that we’re hiding there. Yes, I believe that there is some pretty bad stuff they were working on but many bio labs play with some very dangerous stuff to find ways to mitigate them. So Russia is playing the scare card that they likely started years ago. The Russians put the labs there if defecation hits the rotator so they had deniability and lessen the affects on Russia and the US did not want future issues like Wuhan and keep talented people busy on important research.
Also there was a worry at the time to keep them from going to Iran.
Of course it’s overblown. Yes, initially there was concern the Ukrainian scientists might be tempted by offers from Iran, Iraq or other bad guys if not given proper paid positions in Ukraine. In addition, almost every country on the planet has biolabs for surveillance of emerging diseases. We fund or help fund (andcrun) quite a few in countries that cannot properly fund and run them on their own. These are the types of biolabs Ukraine has.
When Nuland said what she said as quoted in post #75 on this thread it was just more of her fear-mongering. She had already been claiming the dastardly Russians were going to use chemical and biological weapons, blow up a nuclear plant, etc. She couldn’t wait for her little drama queen moment of speculating how the wicked Russians would get hold of stuff in those labs ... and ... gee, how evil Russians are.
Now the Russians are turning that around on her and throwing it back in her face. Typical tit-for-tat propaganda stuff. Propaganda flying both ways.