alt Hacker NewsNo, pilots should ensure they're current at navigating without GPS because it can fail, just like pilots practice engine failure procedures and every other emergency / non-normal procedure. That doesn't mean it should be "randomly disabled" for the same reason that you don't test software in production or randomly turn off the engine of the plane. Obviously.
We don't know how it failed. Maybe it displayed their lat/long perfectly but at the wrong altitude. We think of failure as obvious, but it is often nearly impossible to tell unless you are looking for it.