Is the statement "it is wrong to torture innocent people for fun", logically necessary in the same sense as "2+4=6"? Or could there (in principle) be a universe that functions according to completely different moral laws?

I don't have expert knowledge about the epistemic status of mathematical truths, but I can report on my intuition that it is perfectly clear that there could exist a society that genuinely believed that it was morally acceptable to torture innocents for pleasure but not at all clear that there could exist a society that genuinely believed that two plus four was equal to five. So, my sense is that the two claims you present have different statuses. Your question, however, is not about whether a society could treat that statement about the immorality of torture as false. And, likewise, your question is not about whether or not there exist specific moral beliefs or systems that endorse the truth of that statement. Instead, the heart of your question is the thought that there might exist "moral laws" that demonstrate that the statement condemning torture is necessarily true. About the notion that the universe functions according to moral laws, I would draw your attention to a recent discussion by the...