Sorry, posted too soon. I just got so annoyed with the opening claim that proposed legal changes in the UK and US have to do with some people wanting the state to choose your "gender." As far as I know no law has been proposed to force people to perform masculinity or femininity. We are talking about the ways in which the state deals with people according to their sex.
Having gotten over that annoyance, the rest of the article gives a reasonable overview of many of the issues.