The patches could have been written by humans, it doesn't matter that much. Or written by a clanker and polished by engineers. The difficult part is usually not in writing the patches that fix such vulnerabilities, but in finding the vulnerabilities. And these days it's even harder to exploit them, since you need to bypass modern hardening features.
The product is being provided to some of the most influential companies. That can definitely serve to Anthropic's advantage. (Regardless, I suspect the hype is real.)
Imagine you were making purchasing decisions about which LLM-based coding tool to use.
If one of the possible vendors convinces you that that they have a next gen model that is so powerful it found 20+ year old bugs in a hardened operating system, that would undoubtedly have an influence on your decision even if you are only buying the current model.
As it stands this is just a marketing programme for all involved.