"Can be a choice" is not the same as "Is a choice"; just because something is "a" thing doesn't mean it is "the" thing.
On the flip side, to deny that fringe cases exist is no better than supposing they are the norm.
The nature of choice conflates the issue further, though. Because while the way one feels is seldom optional, the way one acts on given feelings always is. Unless you're a hard determinist, perhaps. So does "choosing to be" relate more to choosing to have feelings, or to choosing to behave in line with those feelings? Definitions are vastly more pliable than facts.
But at the end of the day, no one person can stand for everyone else. While it may bear resemblance to or share common themes with others', your experience, in actuality, is yours alone. So if you tell Us that you've made a choice, We'll take you at your word for it. And if instead you tell Us that you were born that way, again We'll take your word. But when it comes to broad statements that claim to be both universal and definitive, We remain skeptical.