I am bumping this thread because I was wondering it myself. I can't claim the mathematical chops for understanding Noether's theorem, but perhaps someone can give me some idea/well-informed speculation about this question, or even if it's sensible.
Leonard Susskind is perhaps the most reputable physicist to use the term "conservation of information" as a synonym for unitarity in QM. Wikipedia tells me unitarity implies "probabilities are numbers between 0 and 1 whose sum is conserved". So we seem to have some sort of conserved quantity here... although probabilities seem quite different a sort of thing than energy or momentum. So can we point to a symmetry in nature that reflects the fact that the square of the magnitude of a probability amplitude is conserved?
Hope I've understood this correctly, thanks