At one point, NA1 had some of the community maps on it. I think on one of the server updates the map rotation was rolled back though, hence why the ats maps, as well as other maps like the conan map are gone. Infact, sometimes I notice that the EU server maps end in ATS.
Unfortunately, you can't just put someone/a group in charge of the maps, because I think only chadz and cmp have the ability to change map rotations, and I believe there is some sort of a problem with either wse or the fact that not everyone has the beta client that further adds to the difficulties.