Because it isn’t YGO without DMG.
Good Smile has put up Dark Magician Girl for Preorder on their site.
The figure costs 6480 Yen to buy.
Pre-Order lasts from August 9th to September 7th, 2016
The figure comes with a Magic Formula accessory
Those looking to buy her, the partner shop listing should help with the matter.
Those that pre-order get a Dark Burning Attack accessory: