It only ever drops once after they converted it to a craftable weapon. Unlock crafting by starting The Witch Queen campaign then pull a copy from Collections.

[quote]I did presage twice, once with my first drop of dmt I got maybe 3 or 4 years ago realized I probably didn't get the craft able version because i had the og one and I dismantled it just to do the mission again and yet again no drop. Why???[/quote] I believe you have to go to the director, then the legends tab to get it, but only during a week where presage is the mission in rotation. For whatever reasons they did not add the exotics to the portal missions.