Clearly its someone that doesn't bother doing 2+ hours of endgame raid sessions and thinks, oh look pretty colors and flashy effects, lets ramp those up to 1000%, i bet the players will like that.
I can also name a few encounters from last xpac that they didn't bother adressing, and the ones that weren't that bad are also eye searing now with the graphical changes.
Savage raids.:
.P3s (fire bird with all kinds of reds/oranges all over the arena mashed together, instant classic);
.P8s part 1 (wasn't that bad before, but now it has heavy contrasts all over the place, wich makes colors or lights migraine inducing);
.P12s (as you mentioned, just overall blinding...won't even dare trying it now);
Extremes.:
.Mothercrystal (another one i wont bother trying now, it was already awful before with full effects on the last phase with the waves and hydaelyn flashbangs)
.Abyssal Fracture (dark themes with surprise white bright fullscreen flashbangs all over the place)
Can't wait to stumble in more old/new instances with the badly tuned contrasts / lighting and DLSS/FSR cheese grater scaling + forced motion blur.
Another great discovery i stumbled upon (don't know if it was already mentioned in this thread), in display settings > character lighting slider, it changes all the - PC's / NPC's / Mounts / Enemies - lighting at the same time, meaning, be prepared to be blinded by any of the mentioned that have any sort of light effects / reflections / agressive colors going on if you dont set this crap to 0 (do you like lightbulb glowy mounts, now they can become your personal mini sun, great stuff).
This slider is another option they could now easily sepparate in 4 different sliders with the lighting changes.:
.Your character
.NPC's + other friendly players
.Enemies
.Mounts + minions + pets
But no lets cut corners and mash it together in one slider.