I don't understand. "(S)he" pronounced is pronounced like "she"? How is anyone to know that there are brackets? And what is this kid going to do when the other kids start asking, "Are you a boy or are you a girl?" Is (s)he going to say, "I don't know. Nobody will tell me"?
As the mother says, if people think it's a girl because of the use of (s)he or sneak a peek during a playground diaper change, "that's their journey". The entire family obviously knows the gender of the child - the false notion that it is being kept from the child is histrionic silliness in the rush to find fault. Their "dangerous experiment" is to withhold an answer from people they feel are asking Storm's gender in order to modify their behavior in "gender-appropriate" ways. For example, shopkeepers who feel disdain for the purchase of toys or clothes designed for the gender the baby is not, like the one who was horrified that the mum was going to get Storm's big brother a pink feather boa he wanted.
One would assume an 18 month old baby wouldn't have much to say to the question "are you a boy or a girl?" It is statistically more likely than not that by the time the child is of an age when (s)he can verbalize any kind of response, (s)he will already be primarily attracted to the general accessories of whichever gender (s)he happens to be and the "experiment" will be over.
Would I raise my own kids this way? Probably not, but am I going to join the mad rush to condemn another woman's mothering style with no information apart from this one single detail? No, as far as I can tell from their interviews, both parents love and support all their kids unconditionally, and all their efforts are motivated by a keen interest in their children's well-being and fulfillment.