Does the ant-reflective display have an effect? Probably. But why would the demo models not have the same display as the production models? The models sent out to media outlets didn't seem to have this "problem" either. It would have been reported on BEFORE the devices shipped out en masse. Of course, people will cry out and say that Samsung did this on purpose as part of its marketing (without evidence). Since, "bate and switch" schemes are illegal in most countries, I don't think Samsung did it as a scheme to sell more phones. It would come back to bite them hard. Samsung, if anything, is not stupid.
I have my display set to auto brightness. I did notice that color saturation seems a little more vivid on brighter settings and flatter while dimmed.
I am wondering if it has to do with Progressive Width Modulation (PWM). I remember reading a recent article about this and the S24. Samsung adopted an iPhone display feature:
Samsung adopted a little known iPhone feature to help make the Samsung Galaxy S24 family's display better than ever.
news.yahoo.com
Increasing the PWM to alleviate the eye strain that causes some (many?) people to get nauseous could have affected the perceived color saturation. Does it affect the color space that Samsung displays use? If so, then I could see Samsung making the conscious decision to increase the PWM at the expense of vividness and perceived saturation. Since we become accustomed to Samsung displays being over saturated to begin with, people would almost immediately notice the "flatter" look and complain. But Samsung would rather have people complain about the perceived lack of saturation than people complaining about getting sick while using its phones. Furthermore, eye strain is a real issue and has become more of a problem with people always being face down in a phone or tablet. So the PWM scenario makes sense.
So why do the demo units look "normal" so to speak? Samsung knows that those will not be used by people for more than a few minutes at a time, so PWM induced nausea would less likely occur. It shipped demo units with the lower PWM. That, by the way, is just an assumption.
Whether it is because of the flat screen, the anti-reflective properties or the increased PWM, or a combination of them it is largely irrelevant. Two of the things that help me decide to upgrade from my S22 Ultra was the flat screen and anti-reflective properties. The increased PWM is icing since I have never experienced PWM induced nausea.
I am liking my S24 Ultra. It is not a big enough problem to want to send it back.