I have yet to see a documented example of a system prompt leak that was NOT the real system prompt. Have you seen one?
I have yet to see a convincing proof that there is a teapot in an orbit around the sun between earth and mars.
The people who can debunk these system prompts claims have zero incentive to do so.
The fact that a lot of these "leaks" happen yet non of the prompts are the same or even seem to be different iterations of the same family of system prompts, should tell you all you need to know.
My experience has been the opposite: the way you confirm a system prompts leaks leak is to try it several times and check that you get the same result, and I've seen that done many times over the past few years.