This is how you improve GAC, Prove me Wrong!

Terrible idea. The problem with your idea is there would still be people whining that their 1 mil gp account is playing a 2mil gp account, or that someone with 1.99 mil gp gets to play 2mil and under and someone with 2.01 mil gp has to play up to 4, which could be a huge difference in roster quality. Also, by forcing everyone with 6 mil gp above chromium you are 1.) Probably rewarding the low effort players with even more crystals and encouraging that behavior which might decrease spending. Why spend money or play more when I can sit in aurodium for nothing? And 2.) You'd still have a "wall" of lazy high gp accounts sitting someplace that'd you'd have to play and possibly lose to, just that you'd have more gp. 

It was mentioned in another thread, I do think maybe <750k-1mil should maybe have a league no one higher can fall into to learn gac and get some experience.