If OLEDs are 'designed to fail' they've certainly gone about it in a very roundabout way - there would be much easier ways to do planned obsolescence if that was actually the goal of display manufacturers.
I'm pretty sure there's something to it but I'm no expert. Five years later and my TV is just fine.
A monitor displays items that can stay fixed in place a long time, hours or even days.
Not the same at all.