Since the hypothetical brokenness of SHA256 is unknown, can we be sure there is a "correct" way to implement "other purposes"? Surely, it's conceivable a new at

Since the hypothetical brokenness of SHA256 is unknown, can we be sure there is a "correct" way to implement "other purposes"? Surely, it's conceivable a new attack could exploit an unforeseen weakness in all those uses.