Three reasons this is insane:
1. Not telling people if you have a boy or a girl (once the baby is born) is very weird behavior. By extension, these parents are making their child very weird. Before the child puts on its first brown and orange turtleneck, before it has even picked its nose and eaten it or accidentally wet its pants in public, this child is already a complete oddball. Might as well lead the kid to the corner and hand him or her a pot of paste and a spoon.
2. Gender is not a choice. Veganism is a choice. Gender is determined by your DNA, the level and types of hormones coursing through your blood, and a bunch of other things that would probably make more sense to me had I taken Biology instead of North American Literature. Telling a kid they can choose their gender is like blindfolding them for the first few years of life and then letting them decide whether or not they want to see when they get older.
3. These parents are allegedly doing this because they don't want to make a big deal out of gender. The best way to not make a big deal out of gender is to conceal your baby's gender, get interviewed by the local paper, capture the attention of the national and international press, and end up the most read and commented article online all week. Way to fly under the radar, guys.
I can understand not wanting to stereotype your kids. I get the gender neutral name, I can see letting your daughter play with cars. Hell, I even understand letting your son wear nail polish.
But if you are born with a healthy child, for the love of g-d tell us whether it's a boy or a girl.
We promise not to judge you for it.