I'm assuming that generals and admirals are less skilled or prepared to pilot aircraft, as their primary duty is management and leadership, not flying.
Thus GFOs probably ought not be allowed to pilot, but please see the question in the title.
What other GFOs of NATO Rank OF-6 or higher died, while piloting in a war?
There are two types of people who make it to general.
The first type consists of officers who are personally outstanding in combat. On their way up the ranks, they were so good at shooting down enemy, that when they were given the job of training and leading other men, these subordinates also excelled at personal combat. In their cases, they are among the best "soldiers" in their unit, in addition to being generals. An example in the Army was General William Dean of the Korean War, who personally wielded a bazooka during a battle. (I'm using army officers, since I know them better than air force officers.)
McAndrews and Worley were both this type of general. Yes, they were tasked with "planning" the operations of others, but for such men to do this job, they have to go out to the actual battlefield to get the "look" and "feel" of it for themselves. If that's what they need to do in order to "lead," most of them are given permission to do so. (Consider the size and ranks of the "entourage" that went down with McAndrews.)
The second type consists of officers who aren't so combative or good in the field, but excel at staffing, planning and similar functions. Among army officers, George Patton was the first type of general, and Mark Clark was the second type.
During World War II, there was a Soviet air marshal Alexander Pokryshin who got there by being an "ace" pilot. Only a few aces make it all the way to general, and the ones that do train or induce others to do what they do, successfully. In Pokryshin's case, he basically "re-vamped" Soviet air tactics to make them competitive with the Germans. To do what he did, he had to personally lead others in combat and "learn" (second hand) from their mistakes.