Claiming that some people are dishonest is a trivial truth.
But the claim was people who use generative AI tend to hide the fact they used it , and to my understanding, this says: most people are dishonest about their ai usage.
You and me see the opposite of that claim happening. The sheer number of ai disclosed games clearly tells that "people who use gen ai" are not hiding it. Not in significant numbers. So, no, they do not tend to hide that they used it.