Samsung S24 Ultra onwards have the anti-reflective “matte” coating (diffused vs shiny) while the S26 Ultra is the first with the dumb “privacy display” feature.

It’s neat tech, but it significantly reduces the resolution when enabled, it has worse viewing angles when disabled (since half the pixels are less visible when viewing side on) and the feature is done better with a cheap screen protector. Pretty cool that you can use it for notifications, but I think that’s the only part-of-screen tinkering you can do with it, it’s that or the whole screen, so you could just set the notifications to hide message contents?