XB1S 1080p vs 1440p: Look the same

It would entirely depend on the game which graphics modes they internally support. You can display Pac-Man image at 32k, but that won't make it have 32k of detail. The resolution the game is rendered at, and the output of the scaler, are often two very different things

So the update for native 1440p is all just some gimmick?

the Xbox one s will upscale that's it, it does not have enough power to output those resolutions for games at all, all games will play 1080p or less depending on the game.

it is 9 year old hardware, it does not have the power, it will take the 1080p image and stretch it out to 2k or even 4k and the image will not look brill, the 4k aspect of the s is for streaming movies at 4k which it can do.

Sorry but that doesn’t quite help.