Someone said that on the PTR Blizzard made it so that WoW would not load Arbitrary MPQ's. It can still load model edits. After you make an edit you can add it to the real wow MPQ archive. Go to mywarcraftstudio and go to pack. Choose edit MPQ archive. Then you can choose to add file to archive. for example I added the noggit'd file World\Maps\Kalimdor\Kalimdor_40_30.adt to the patch.MPQ in my wow data folder. It caused my WoW game on the PTR to crash due to that file being corrupt. But still unless no none makes a modeledit fix it still won't work. With a modeleditfix it is only a tiny bit harder because you have to add it to an archive on your own after you download it.