Yeah, LLM coding tools can help in reverse engineering completely novel and proprietary systems.
I get the whole anti-AI stuff prevalent on Mastodon, I really do. The code quality when using them for development is really horrible, while you'll get something that fulfills the requirements the tech debt - and security holes - is through the roof.
But.
There's actual gains to be had from using them as well. I just tried using Devstral 2 to analyse some flash dumps I'm definitely sure has not been in any training data ever and yeah, that saved me time. The analysis looks exactly like what I would have come up with myself after about 10x the time the model needed.
If you still believe LLMs "can only repeat what's in their training data" you're simply wrong.