Tbh I was fairly happy to see an article that reminded people liberal enough to care about trans issues that having a gender nonconforming child is not the same as having a trans child. I would rather not have been made to worry about what gender I actually identify as as a kid. The fact that there was the word tomboy and it was something other than a girl but also meant i didn't have to prove being a boy, was enough for me back then.
But now as a fully grown person I see an overlap between what I thought of in my head as "tomboy" with the trans spectrum. I sort of identified with it like it was an actual gender - I'm not a girl I'm a tomboy (I could switch that out for my previous less convincing mantra of I'm not a girl Im a boy). And I am always and will pobably always be unconfortable with people referring to me as a girl or seeing me in really gendered ways. Or catching myself in the mirror when I'm not expecting it. Dunno what that all means but there we are.
Anyway, there are tomboys who grow up to be feminine, there are tomboys who grow up to be butch women who love being women, there are tomboys who grow up awkwardly and boyishly like me (and probably should choose one of the other options), there are tomboys who grow up with a strong non-binary identity, there are tomboys who are actually transguys who transition to various extents. I prefer not getting into the complexities of gender with children. Just let them be for a bit and see how they choose to be.