My Gigabyte OLED monitor is 2 years old now and gets used for many hours on most days and shows no changes. I bugged out the time counter for a few months by putting the panel in to service mode, but still it is up to 4040 hours, or 5.5 hours per day for 2 years.

Your other post mentions the screen brightness dropping with white menus open, but that is not because of a burn in protection feature, but instead it's because of limits on the total power consumption of the panel (either because of power efficiency laws, or too much heat).