Skins from The Assault Collection are not obtainable through the weekly drop.
The Assault Collection is a Valve-made collection of CS:GO skins introduced on 14 August 2013. The collection consists of 2 consumer skins, 1 industrial skins, 2 mil-spec skins, 2 restricted skins, 0 classified skins, and 0 covert skins.
The Glock-18 Fade is undoubtedly the most sought after skin from the Assault collection with players using the AUG Hot Rod and Negev Anodized Navy in high risk trade up contracts.