I do not imagine that things divide so clearly along these lines.
I think this idea comes from two directions: firstly, LLMs are relatively predictable, so given the same prompts and review processes you're likely to find the same bugs, and secondly, if you're using the free or cheaper LLM tiers, your conversation is likely to end up in the training data and so become 'known' the the LLM after some time anyway. I think the latter is perhaps being overestimated by the kernel security team (Greg KH's talk on the matter characterised is as "the LLM finds a bug for one person and then decides to hand it over anyone else looking for bugs as well", which really isn't how it works internally).
That "expectation" us far from certainty and it exists for bugs found by humans too, in both cases, caution dictates to follow the standard responsive disclosure procedure.
My impression is that Linus doesn't like dealing with security, it's just an annoying chore he's uncertain about. I hope things change in the future because that attitude percolates down to the kernel team as well and it spells trouble when combined with the size of the project and the new AI developments.
Personally while I'm not going to rail against 'responsible disclosure' I'm not utterly convinced it's the best way to go, and certainly not that it's the only moral option.
The big advantage the LLMs have is their huge context windows, ability to parallelize and delegate, and no attention fatigue or need to sleep. They can think about random combinations of functions and modules all day long until they find a combination that's exploitable. That's hard for a person to do, and its the kind of exploit that probably would never be found otherwise except by another llm-powered thing. Not being a security expert myself, I gather that these AI vulns tend to be small needles in very large haystacks that normal people just would never have the patience to search.
But if you found something yourself, then it's something that's simple enough and involves a small enough number of moving parts that you can keep it in your head all at once and recognize the problem and correctly reason about its consequneces, which probably means it's easier to exploit, and therefore more dangerous if made public.
It feels a little backwards, and it might still be backwards, but if there's any benefit i think it's along those lines.