It is very hard to maintain "excess" muscle on feminizing HRT (the body has different muscle to fat target ratios depending on hormones), and impossible to (re)build it. Someone would have to work disproportionately hard on maintaining most of their "male advantage" a year in. I'm not an athlete, but every trans person you ask will tell you that the difference in strength is quite significant. Even if I can just tell from being unable to open jars.
That aside, I really recommend you invest time into that essay. It's an interesting tale about why we have segregated sports to begin with (believe it or not, women doing sports is a relatively recent thing) and how trans people really aren't the biggest interference to the unfairness of it all.