Actually, recent OLED's are more prone to burn-in than the earlier models according to recent testing from rtings.com just last month where they tested the latest LG WOLED and Samsung QD-OLED technology.
Samsung has thrown a lot of shade at LG's OLED TVs over the years over potential burn-in problems. Have the tables finally turned?
www.digitaltrends.com
This could be due to the panel makers driving them harder with better peak and sustained brightness. I personally think OLED isn't the way forward and they should instead concentrate on making MicroLED production ready.