i think they are referring to statements that they have "solved" hallucinations and it wont be a problem anymore (which it obviously isn't yet anyways)
My guess is that post-training has gotten a lot better in the last couple of years and what people are attributing to better models are actually just traditional (non-LLM) models they place on top of the LLM which makes it appears that the model has increased in quality (including by seemingly fewer hallucination).
If this is the case it would be observed with different prompting strategies, when you find a prompt which puts more weight on the post-training models.
Apparently not, because no one but you implied that they had been.
There are prompting strategies that improve the odds greatly, but like the GGP, you've made up your mind, so it's a waste of time to argue otherwise.