They never say which last letters are associated with which sex. I'm guessing that "o" is usually male and "a" is female, but, what about the other 24? Is "n" usually male ("-son")? Does "y" have a bias?

(Regarding sex vs. gender: yes, they aren't perfectly correlated and some people don't stay with their assigned gender, but AFAIK they often/usually choose a new name which probably matches their gender? Thus why "dead names" are a thing.)