Floral had it right. Nonbinary is like a religious or political belief. It has no bearing on anything. She's still a woman and it's quite right for her to compete on the women's team, which should be based on whether someone is a (biological) woman.
I don't believe Quinn should be allowed to rename the women's team, but to be fair, she hasn't tried to do so to the best of my knowledge.
If there were a significant number of NB athletes, perhaps if they wanted they could form a NB team. But why? It would be no more sensible than forming a Christian, Muslim, socialist or conservative team (such teams probably do exist, clubs and churches with their own teams perhaps, but surely at Olympic level part of the whole ideal is to be inclusive). Much better to just define the teams by sex!
It is sort of sad that Quinn feels the need to dissociate herself from womanhood but she has that right.