LLMs can and do regurgitate code without the user’s knowledge. That’s the problem, the user has no way to mitigate against it. You’re telling contributors “use this thing that has a random chance of creating infringing code”. You should have foreseen that would result in infringing code making its way into the kernel.
If you don’t feel comfortable about where some code has come from, don’t sign your name.
The fact LLMs exist and can generate code doesn’t change how you would behave and sign your name to guarantee something.