i'm not sure. i only know the 1440p panel by LG, Gigabyte and upcoming asus that is 100% using the gen4 oled panels with x2 times burn in resistance compared to the previous gen 3. This applies to both qd oled and woled because they both using the EL3.0 over the older EL 2.0 materials on the panel for that burn in resistance.

The main difference between the qd oled and woled gen4 however is that woled improved their brightness, improved the color to catch up to qd oled (so this is no longer their weak point against qd oled where before it was because it was less colorful), they improved the text clarity (was it fully resolved? i don't know. but according to the reviewer for LG monitor they said it still had fringing but it was much improved than before, so i am guessing he meant it's fine)
Only reason i didn't get a gen4 was there was no availability at the time and i couldn't wait. But now in the market the gen4 is available and for rougly the same price i had paid for the gen3. The only reason not to get a gen4 is if it's matte and you have your doubts about that. Everything else seems fine though. And if you can wait a few months, sometime in Q4 2025 asus is releasing a true glossy black 1440p gen4 woled.

Not sure about the 4k resolution monitor, have to dyor 

tftcentral might have some info on that.

https://tftcentral.co.uk/articles/4th-gen-p...27q28g-showcase
i asked AI it said this
in short, no. it's considered gen3.

Keep in mind this gen3 vs gen 4 oled panel is a term by tftcentral. What it means is the oled tech developments which is sufficiently different to be considered a next gen tech development.
https://tftcentral.co.uk/articles/qd-oled-g...graphic-and-faq
https://tftcentral.co.uk/reviews/asus-rog-strix-xg32ucwmg

why sell? 2k is self lowball for such a good glossy WOLED