Hey DC is trying new blood now a days. And also,I don't really see Maxima on modern day Superman. It feels appropriate for her to show up when he is on his younger days. By the time Jon is around. There is no reason on why Maxima should go to Earth. And I hate to say it cause I know it hurts since they done it to use with 3 Superman characters...but the only place I can see her modern day is in GL stuff.