My wife and I have three boys. The bookends are adopted. The oldest at birth, the youngest at 7 y.o. The middle boy is the bioboy.
We did not know the sex of either of the oldest children. It was a joy to us to have the surprise of finding out whether we were having a boy or a girl on the day of delivery. We had plenty of shower gifts that were more neutral - browns, greens, plenty of orange

. Our nursery was ocean-themed. Lots of murals of fish, fish sheets, fish lamps, light up aquarium night lights. There is plenty out there that is sex-neutral. Obviously, based on the surprise factor, I am so very happy with our choice to not demand sex identification.
However, I don't get into the theology of it. God created my children in His image. He knit them in their (respective) bio-moms wombs. Our decision was based purely on the joy of the reveal in the room, looking in each other's eyes and agreeing on a name. We got to pick male and female names. What fun we had for weeks going back and forth! (In addition to not knowing sex, we didn't tell anyone our chosen names, boy or girl, until the child arrived. We are such sticks-in-the-mud!) We got to imagine a world with a daughter and a son. We got to share our news as a surprise at the moment of independent life, and that was so much fun!
Ours is not the only way, but I am glad we chose it. We have parented the same way.
WE make the decisions for our children. We don't let others. We have gotten a lot of grief from others about what we allow (freedom!) and what we hold fast (consequences!) We let our kids live. They know the joy of being free with the pain of living with the results of their decisions.
Long term - it doesn't matter what anyone else thinks. Just do what you want to do for you and for your wife, whatever others think doesn't matter a bit.
(Except for my thoughts, of course. They matter. You should wait to find out in the delivery room.
It is so much fun!)
Congratulations on the best thing you will ever do.