I have not seen any discussion on that gimmick. I would think, at a minimum, the 5 year rule would apply and more likely the 15 year rule. But, that's just a quick opinion.
Google AI says: "Changing the beneficiary of a 529 plan may reset the 15-year clock required to roll over funds to a Roth IRA. " I noted the word "may", concluding that Google doesn't know yet either.
