This really belongs somewhere like worldbuilding, not here. But I tend to just answer stuff knowing the result will be discarded...
Mary Gentle has a similar species, who get a gender at the dawn of puberty. She actually points out that in a society that is still very labor-intensive and leans toward huge families as a consequence, it can be very inconvenient for someone to not have known whether they will get the added boost of muscle development and size, or whether they will be in charge of a household of their own children. She has characters who are very well-practiced in fighting, but never attain the height necessary to make it a profession because they become female. Or who grow up male and miss the time they used to spend with children because they are required to earn money for their own spouses, who are tied up at home with their children.
So I think the answer has to depend upon the level of technology and how much that sorts the kinds of jobs people do by gender. In a modern world, where most people don't, for instance, carry things for a living or simply apply force to things for hours and hours a day in attempts to shape them to their will, where motherhood is not a permanent full-time job in its own right, because we don't have as many children as possible, and where even effectiveness in war and personal safety are equalized by technology, there would be no reason to care what gender you were growing into.