Heck i remember reading somewhere that due to the mass taking of penis enlargement drugs the average penis length of humans has increased. Thus with something as immensely popular as a period remover, it wouldn't be unbelievable to say that nowadays human women are just born without periods.I love how the first conclusion you come to is that the entire universe simultaneously just absolutely loses it when a woman starts bleeding and declares the entire thing taboo. It's not even unnatural blood like from an injury, it's fluid from a natural bodily process just like a Galotian's slime or Myr's venom. There's literally no reason whatsoever for a society made out of countless species of fucking ALIENS of all shapes and sizes to freak out about it unless they thought the woman was injured by an outside source and were concerned for her safety, which would instantly be corrected by any humans present. The most likely and reasonable in-universe explanation is that they just used future technology to alter the process into something more tolerable because people don't exactly like dealing with periods and that kind of treatment would be in very high demand if available. It's basic capitalism.
Or alternatively someone running for president of humanity promised hereditary treatments of period away as a campaign promise and delivered when she won.