In-theater military targets have never had a right to trial. When airstrikes are used to kill al Qaeda members, the Administration is not exercising its criminal justice authority.
The "theater" in the Global War on Terror is the entire globe. The United States is not at war with Yemen.
Abdulrahman was not even alleged to have engaged in "military" conduct, merely being a propagandist.
He was not a "target", he was collateral damage of a strike on someone else.
This is not a heated battlefield death. The nature of war is shifting and using aggressive global militarism as an excuse to handwave around the denied due process of a 16 year old US citizen is disturbing.
Is there any place the U.S. is conducting drone strikes that's not on the list?
Who decides who's an al Qaeda member and who isn't?
Is "s/he's a member of al Qaeda" the magic words the admin has to say to not have to provide someone with due process?
There is no due process that protects you at war. This is why we don't want to be at war, and why we especially don't want to be at war with a brand name.