Many men aren’t happy about balding, especially earlier in life. They feel distress at their body not presenting the way they want it to (with hair!). hence, gender affirming care.
I have man boobs, I guess fixing that would technically be gender affirming care because I'm embarrassed of having female features, but balding is really a stretch.
It doesn't really make any sense to say that preventing a natural feature of men from progressing is being done to affirm men.