A pilot engaging reverse thrust mid-flight can break apart a plane:

https://lessonslearned.faa.gov/ll_main.cfm?TabID=3&LLID=34&L...

You really, really do not want the reverse thrust to turn on in-AIR. That would be way worse then then engine shutting down.

I don't mean specifically reverse thrust. I am saying features such as this. The Pilot expects something and computer does something else.

There are usually failsafe modes that disable most of the additional software features. It is pretty rare though for pilots to switch into those modes though since those features are what fly the plan a majority of the time.

It is like the issue that are running into with self driving cars, there is a point where the flight controls become so good that pilots are less likely to intervene when something is going wrong.

It has occurred. Lauda Air Flight 004 was a Boeing 767-300ER that crashed due to an uncommanded reverse on the number one engine.