I have not seen any indication that Rowling, Musk, or Adams assert that trans people are categorically a "major threat". That said, these folks do view trans people as a "major threat" to those athletes who compete in the category that once was exclusive to humans distinguished by having XX chromosomes. They believe, and rightly so in my opinion, that this athletic competition category should remain exclusive to those humans scientifically established (usually pretty obvious at birth) to have XX chromosomes.
Researchers locate neurons in the brain that respond to '0' is in same region as neurons that respond to '1', '2', etc. The empty set (nothing) is apparently encoded differently.
I always figured that liberal radio, e.g. Air America, struggled and failed because that point of view had too much competition from other media, e.g. newspapers and television. Back before internet, conservatives only had radio to hear what they considered their point of view taken seriously and the other side derided whereas liberals had lots of other options to hear their points of view taken seriously while the other side was painted as rubes.
I don't see it as ironic at all. One way anthropologists studying a society can gauge what that society values is to look at the punishments applied for various transgressions. There are severe consequences for transgressions against things that a society values highly. Thus if a society values each human life as the most precious component of their society, then it is not unreasonable if that society places the most severe penalty on anyone who ends such a life. For that "most severe penalty" to be the ending of the life of the perpetrator, if such judgement is determined with grave concern for all parties involved including the perpetrator, is not ironic. It signals to the members of that society that their very life is the most precious aspect of the society of which they are a member.