I'm not saying a computer can't fly the U2, but I do think it'd be more complex than a conventional aircraft. It has some pretty unique flight characteristics. From Wikipedia:

"...To maintain their operational ceiling of 70,000 feet (21,000 m), the early U-2A and U-2C models had to fly very near their never-exceed speed (VNE). The margin between that maximum speed and the stall speed at that altitude was only 10 knots (12 mph; 19 km/h). This narrow window is called the "coffin corner", because breaching either limit would likely cause airflow separation at the wings or tail. For most of the time on a typical mission the U-2 was flying less than five knots above stall speed. A stall would cause a loss of altitude, possibly leading to detection and overstress of the airframe."

https://en.wikipedia.org/wiki/Lockheed_U-2

This actually sounds like the kind of challenge a computer can do VERY easily - much more so than a human.

This speed management is actually handled by an autopilot (i.e. computer) in U2s, using 'mach hold' mode.

Flappy wings, tough to land.

Computers don't fly the F-117, they help humans fly it. The difference between the two is significant.

Those were the 80s computers though. We've gone a long way since then.