The “weapon” here is identifying vulnerabilities that were already present and exploitable by malicious actors?

A very shallow dismissal of my point. Is there no room for depth in your logical analysis?

First of all, we don't know whether this particular bug was already being exploited in the wild. We do know that there is a community of experts looking at the Linux kernel and reporting bugs. Yet this bug had never been reported until now. So either nobody ever looked there (unlikely), or they did and didn't find it. Conversely, the LLM found it with a prompt that even a 5-year old can type. That significantly lowers the effort for the attacker, so much that it changes the game. It is, to use a crude analogy, like deploying firearms in a field traditionally fought with sword and shield. So yes, that's the weapon, and these guys released the stuff to the public with no oversight. That should get some people thinking.