The mill circle is a required skill in the USAG level 2 bar routine. And a mill circle is still a required part of the level 3 bar routine, even if a kip is performed. I can't speak to what you have "heard" or what gyms "tend to do", as some gyms will let girls compete without required skills and take the deduction. There are also parts of the country that set up their own routines under an AAU or YMCA system, I am only speaking to the USAG compulsory routine text.Not a level 3 expert which is why I posted the actual routines. My points was that a mill circle can be gotten around. It is for sure not required in level 2. And as there is some flexibility in skills it is possible that gyms chose different paths. So while a child may look like they don't have the skills they may because they just might be different.
When I do hear of L3s doing kips at meets, they tend to not do mill circles.