Has UA ever changed reward redemption requirements in the middle of a year to increase the required miles? I am young so what do I know.

Why do people think that UA would do such a thing with empty planes and when they are already lowering them during select periods?

At some point UA faces a problem with giving away a lot of miles to generate revenue but also wanting us to use those miles rather than just pile them up, because they are a liability on their books. But I am guessing airlines want to right now generate revenue and worry about the mileage fallout another year.

I am no expert, so I am eager to see my opinion challenged, especially with someone with more facts than myself.