I can see the irony involved, though I'm not trying to be ironic myself. As someone who has skin in the game (well, kinda.. my days of being an athlete are decades in the rearview mirror), absolutely I'm all for equality and compassion and acceptance and respecting people's gender identity - and that does obviously include non-binary.
Now here is where I own up to ignorance: I know all too well about gender-assigned-at-birth and gender identity not matching. I don't know what it feels like to say "I'm non-binary or gender fluid." So I don't know how I would react or answer the question of "I want to play football but I don't know which team to join. I'm non-binary." I can't give you an answer as to how I'd answer that question if I were in that position... so I really can't answer that question for others.
In a perfect world, you're right. We would have more gender-neutral restrooms (sadly, I don't think a lot of Americans could handle that yet). And we would divide sports (hence divisions) by ability and not gender. I personally would have no issue with it... But is society ready for such a thing? I don't know.
This is the kind of thing where I wish someone NB would offer their thoughts myself. Because while I prefer compassion over "being right," I have such little direct knowledge that I don't know if I could give a right answer. This is definitely one of those cases where the best thing to do would be to sit back and listen to those who are non-binary. Especially since Germany's position does give me the impression their thoughts and feelings would certainly be heard.