Given your zone, I assume this is being grow as a containerized houseplant. It is not uncommon for ones grown as houseplants to develop secondary leaders. There is no overwhelming need to remove the second and I'd evaluate how it might affect the appearance before I considered doing so.

Yeah, I grow them in containers but 9 months outside, then into my loft garage. I had one get to 12 feet before I had to give it away (I know they get much bigger)., but I love Araucaria, have a A. araucana in my yard and a A. bidwilli in a container. Will lope off the secondary leader to maintain it as a single leader (when I bought it, assumed it was two separate plants in one pot.