There isn't, today, a good filter for such input beyond that it came from a person or that it came from a probabilistic vector distance algorithm. Perhaps we'll have such qualification in the future to make the distinction in this context irrelevant.
Even if LLMs do become capable of generating usable training output for themselves, they will still not have human personhood.
Personhood as a capacity to participate an an agent in a network of mutual recognition of personhood, however, is likely.
https://meltingasphalt.com/personhood-a-game-for-two-or-more...
What about more advanced ones that have yet to be invented? Will they be persons once they're built?
(For clarity I want to make sure you know I'm talking about de facto personhood as independent agents with careers and histories and not legal recognition as persons. Human history is full of illustrative examples of humans who didn't have legal personhood.)