I was a bit surprised to see that champion is still gendered (championne). In daily speech I almost never hear championne used to refrer to a woman.

Good point. My point is not that the word championne should be concidered wrong.  Clearly your examples prove why is needs to stay put, but when a woman or girl or group of women wins a title, I have heard them called champion or champions.  All I am saying is that in this case it seems the language has evolved and Kwiziq should concider making it an acceptable answer as well.