The only design detail from the upcoming Superman movie (that we know about) that I can't figure out the reason for is the main Superman logo. Why a gold Kingdom Come logo?
What we know about the film so far is that this is supposed to be a more "traditional" Superman story about Clark reconciling his Kryptonian heritage and his human upbringing. With that in mind, I can easily find plot reasoning for most of the design.
The bright colors, trunks, and shield on the back: traditional Superman and possible connection to Earth.
The space/tech lines, armor sections, high collar, and uniform-esque structure: Kryptonian military uniform.
I can easily bullshit justifications for most of the design, except the logo. In Kingdom Come, Superman wears a strange, black and red logo to show his mourning. Specifically, to show that there is still hope in death (though, it may actually be a symbol of revenge or war, but I'll explain later). If you've seen the Arrowverse crossover Crisis On Infinite Earths, you already know this. This explanation is obviously not what this film is doing. This is a young Superman, still coming to terms with his origins, so he's not mourning the loss of everyone close to him. This is why the logo is gold and not black, but why keep the rest of it? I see three, probably obvious explanations.
The first explanation is that the new film or series takes thematic or narrative elements from the comic. In Kingdom Come, Superman retires after the Joker attacks the Daily Planet, killing Lois and the rest of his supporting cast, and the public celebrates a violent vigilante killing him. After these new generation of vigilantes cause the destruction of Smallville (it might have been the entire state of Kansas, which is kind of funny, but I read this book at my local library years ago, so I'm choosing the less extreme option), he comes out of retirement with a new Justice League to reestablish the tradition notion of heroism, though Batman believes Superman is simply looking for revenge. We know that in the new film, a strange version of, what appears to be, the JLI that may be funded by Maxwell Lord is in this film and we know that an authority film is coming, so maybe this new Superman will be introducing, what we would call, a more traditional form of heroism to this already established universe. It would certainly be an interesting, bold statement to make after the last decade of "subversive" takes on Superman.
It could be because this shield is harder to read than the traditional one. If the movie is about tackling Kal-El, the Kryptonian, vs Clark, the human, and this is still the symbol of the House of El, then maybe this symbol was picked because it looks less like an "s", making it feel more alien. Maybe it is a symbol of Krypton in Earth colors.
Or maybe, just maybe, they just liked the Kingdom Come logo. Maybe they wanted to set this Superman apart from other versions and pick a logo from the comics that they liked. Superman and Lois is using the traditional logo, My Adventures with Superman is using something similar to the electric logo, and the DCEU used a variant of the 40's logo, so they looked at what was left and chose their favorite. It wouldn't be the first time they used a logo for no reason (why the fuck did the DCEU Superman use the 40's logo).
Who knows, I'm probably wrong. I just know that I'm currently mixed on the suit overall and trying to sort out my feelings on it. What ya think?